Gronn link - LCA + Energy

GRØNN LINK Renovating – Redesigning Incase of Life cycle assessment

Project description The L&S mechanical workshop is an industrial building built in the 1960s. The building has been extended and renovated at least five times after the initial construction, with a construction time span from 1963 to 1998. It is a steel structure with concrete slabs and parapet walls. The facade consists of insulated steel plates and the gable walls are leca blocks. The building footprint is 3500 m2. As of residential developments in the area of Nyhavna, the population around the workshop will significantly increase in the near future. The building’s owner is today considering disassembling the building and using part of its components for constructing a new residential block. On the other side, the community of Svartlamoen is looking at the L&S building as the opportunity to have a buffer between their community and the new residential developments.

How can the building represent a meeting point for the new and the old, not being an extension of neither Svartlamoen nor the new development, but rather a shared space where people belonging to different communities could meet and share?

The program of the building considering alternative scenarios in different concepts: keep the building, transform it, or disassemble and reuse (part of) its component. The proposed concept should combine a vision for the future of the building with convincing numerical LCA analyses, supporting design choices. The shelter of the building could host half climatized and climatized spaces in the same shelter, conditioning the need for insulating or not the building.

Site: Building footprint _ 3500 m2

History Nyhavna is a port area in Trondheim, between Nidelva in the west, Lademoen in the east, Ladehammeren in the north and Nedre Elvehavn in the south. The harbor area at Brattora is located on the other side of the Nidelva, which passes between Nyhavna and Brattøra. In 1912, a new harbor plan was prepared for Trondheim. The Port Authority built the Lade pier from Pier II, and the Coal Crane Pier was framed. This area, between Nidelva and Ladehammeren, was named Nyhavna.

The two German submarine bunkers Dora 1 and Dora 2 from World War II were built at Nyhavna. Dora 1 was completed in the summer of 1943, while Dora 2 was never completed. Dora 1 was later converted into a warehouse and office building, Dora 2 was left to the port of Trondheim after the war. In 1943, Dora was bombed by American planes. Dora was largely unharmed, but buildings in the rest of the area around Nyhavna were badly damaged during the attack.

Urban context :

Svartlamon is norway’s first urban ecological experimental area. The area is organized and operated according to principles of sustainable environmental solutions, flat structure, transparent economy, low standard and affordable rentals. The svartlamon area although small has a lot of good quality functions.

Nyhavna is a busy industrial area with construction activities and heavy traffic. It is also known as an arena for urban development, innovation, and a space for artists and art environments. Therefore, the Trondheim Kommune wants to enhance the zone through strengthen all of its potential urban life and connect them to the city center future strategy.

Neighbourhood

LCA & Design approach The built environment demands around 40% of the world’s extracted materials and wastes from demolition. Sustainable design is a trending construction approach where all the design decision focus on minimizing the impact that the building operation and construction have on the environment.

Incase of L&S building, to calculate the GHG emission from existing structure and New construction the Online tool OneClickLCA was used, referring to European Standards EN 15978.

The parameter that LCA is being used to find is the Global Warming Potential (GWP) measured in CO2eq. In the initial stage of the design, a comparison of emission from materials was done before including them in the project.

The study hypothesizes that the existing structural elements of the building, like steel columns, slabs, retaining wall are in good conditions to be used over for next 60 years. The project focuses on adaptive reuse of the structure. Mix-use functions are proposed in the structure to serve the existing community and support upcoming development.

PHASE 1 - 1963

PHASE 4 - 1980

PHASE 2 - 1966

PHASE 5 - 1996

PHASE 3 - 1978

PHASE 6 - 1998

S.no

Building elements

Building materials

Area (m2)

Volume (m3)

Weight (kN/m3)

Mass (kg)

1

Foundation

Concrete , cast in situ

5093.19

1168.29

1604.7

2810436

2

Floor

Concrete, Cast In Situ

5393

808.95

236

1946036

Steel Plate

88

1.76

-

-

Metal -Steel

274

0.55

231

4304

LECA Blocks

329

32.89

-

-

Gravel Panel

137

2.74

-

-

Gravel panel fixed on concrete wall

275.2

30.27

47.22

66245

Corrugated Metal Sheet - 10mm

90.42

9.49

23.61

21761

Corrugated Metal Sheet - 15mm

821.95

88.17

70.83

197491

Concrete In situ

589

176.68

424.8

425011

Cement Blocks

274

27.43

-

-

Insulation

69

5.51

0.1

1

Concrete Masonry Units

2581

530.54

731.8

1276718

Gypsum Wall Board

138

4.13

118.7

4535

3

4

External Wall

Internal Wall

S.no

Building elements

5

Curtain/Windows

6

7

Building materials

Area (m2)

Volume (m3)

Weight (kN/m3)

Mass (kg)

Glass

377.85

4058.19

9.45

22791

Aluminum

19

0.44

-

-

Frame

11

0.1

27.41

55

Metal Sheet

38

0.72

462.1

5640

Plastic Door

169

3.18

-

-

Steel, Paint Finish, Ivory, Matte

354

6.63

692.8

692.8

Asphalt, Bitumen

3158

63.15

91.4

147091

Cardboard

3158

63.15

307.9

495508

Insulation

3158

315.76

307.9

2477545

Steel ASTM A36

3158

94.73

307.9

743263

Column (465 x 610)

Concrete, Cast In Situ

692

88.71

731.6

213384

IPE - 300

Metal - Steel 43-275

547

3.78

3234

28447

Beam (North_Beam)

Metal - Steel 43-275

762

2.96

5698

24108

HP-Bearing Pile: HP 12 X 63

Metal - Steel 43-275

236

1.62

693

65127

Doors

Roofs

8

9

● ● ●

● ●

Depending on the installation system, fiber cement products can be removed by unscrewing or opening the studs. Thus, the best solution is to reuse the product the material in the same place, i.e. facade or in internal wall.

This product contains 25% to 40% cement, hence the CO2 emissions from it are relatively high.

Concrete is a heavy CO2 emitting material, and have adverse effect on environment if not disposed off carefully.

The concrete can be recycled into aggregate after it has been crushed and processed.

Recycled concrete can be used as a bed foundation to lay underground utilities. This concrete can be also used in walkways to provide plain and durable surface.

Concrete & fiber cement

●

●

The leca concrete blocks has good sound and thermal insulation character, the blocked can also be reused if handled carefully in demolition and can be reused for internal wall partition.

In case of using them as there are on the site, more insulation should be added, preferably on the exterior wall to avoid thermal bridges and create a good thermal indoor environment.

Leca concrete blocks

In the production of leca block, building product declaration specified that energy used for extracted of the raw materials is about 400 MJ/m2 to generate high temperature for processing leca and consist mainly from fossil fuel. Biofuels can also be used but this would mean a much longer production time related to slower heating.

Almost 100% of the glass can be recycled to be used in production of few products mentioned below.

1.

2.

3.

4.

5.

Float glass Aggregate on concrete Foam glass Concrete as a fine aggregate Production of insulation.

The existing glass of the structure were in good condition to be not replaced for renovation. The decision of changing the glass facade and windows could be justified only if they are replaced by Low U-value glass for energy saving.

Glass

Structural steel : Steel I,C and rectangular hollow sections for columns, beams, bracing steel trusses used as portal frame. ● Aluminium T/L profiles : These structural elements could be reused as suspended ceiling, for window frames and sent back to factory for making future products.

● ●

Corrugated steel sheets : Could be reused as cladding on external walls to withstand against wind and rains. Resistance to deterioration and fire.

Aluminium & Steel structures

●

Strengthening the steel structure.

Nuts and bolts easy to replace without damaging the elements assessing damage - use anticorrosive paint for rustic steel elements.

Welded connections

Concept As per the new Framtidsbilder Trondheim Sentrum 2050, Nyhavna and adjoining area are set to become fjord facing residential zones. The L&S building sits in a strategic location of intersections and the idea is to aims to introduce an inside-out landscaped park that is also usable through the winters. It would include a public library, serving areas, indoor garden, spaces for commercial use, office, conference area and gym. The concept aims to keep and reuse large parts of the existing building.

As a design intervention, two glass inserts are introduced to bring in visual connectivity, daylight access as well as to facilitate a seamless inside-out transition. It also contradicts the blocky massing of the existing structure and brings in a fresh interesting element to the project.

This zone can function as a semi-climatized zone during the summers while it can be closed off during the winters to act as a greenhouse to retain greens inside in spite of the cold & snow.

Structure zoning Greenhouse Zones, that brings a large amount of daylight into the structure, maintain internal comfort temperature and creates an active space throughout the year.

Access zoning The separation of access zone is designed vertically and horizontally to maintain public distribution. This also give design flexibility for multiple entries as per the requirement of the respective zone

Energy zoning The segregation of climatized and Semiclimatized zone will reduce the heating load of the structure and will also create a safe indoor space in winters

1, 4

Site

Site entrance & exit

2 Indoor plaza

Langeland & Schei (L&S) building is located very close to Lademoen and lies along the bicycling and jogging tracks. It is also near to existing residential and is central to the proposed developments. Taking advantage of that, the pedestrian and cycle paths have been kept central to the site plan to have maximum intersection and footfall.

3 4

Outdoor plaza

5

3

Amphitheatre

6 Event space

2 1

5 6

The amenities also provide initiative for the general public as restaurants, OAT, library, cafes etc. The back of the building has a shared surface giving access to the unloading vehicles for the workshop and direct access to the co-working spaces.

Vehicle path Cycling path Pedestrian path

First floor plan

Floor plans The first floor has been designed along the landscape connectivity to give maximum access into the building. The organic lines cut across the rectangular geometry of the existing structure, separating the existing and the new. Towards the west are the public areas with plazas and space for temporary activities in the atrium. Retail shops are on either side while the deck with cafes and balcony is in the first level.

Second floor plan

The deck, made of CLT, is new addition that facilitates the connectivity on the second level. This enables to make efficient use of the volume of this structure. Gym is located to the North for separate access so that they can operate beyond work hours of the rest of the facility. The Restaurant, located above the gym, also benefits from the access to views overlooking the fjord and fjell. Towards the East (or back) are the co-working areas and the workshop. This gives them privacy and facilitates direct access, both vehicular as well as pedestrian.

Energy Concept Multiple choices have been made in order to minimize the final operational energy need of the building. Initial temperature and energy analysis were made in the concept stage to find out the potential benefit of glazed atriums in reducing the heating needs of the building.

This analysis to define the benefits and design of the glazed atriums.

The addition of the Atriums help bring in adequate solar access into this structure as is evident in the daylight study. They also add a distinct point of interest to the whole project with minimum intervention. Functionally, they act as greenhouses which not only helps maintain the greens but also heats up much quicker during the days (especially on cold days) and this heat can help reduce the heating needs of the adjacent areas. Most of the materials which have been removed to introduce the atriums have been reused back into the project as wall claddings or internal partitions.

Energy simulation resuts with ETFE and insulations on exterior walls

With Atrium

With atrium & skylight

Second floor

Daylight Analysis :

First floor

Existing

The design solution is to introduce a climatized atrium space, which acts as a greenhouse while also bringing in ample daylight. This helps maintain adequate ambient daylighting throughout the building as well as cuts the building energy demand from electric lighting power. It also helps introduce transparency by introducing a visual connection to the outside and surrounding landscape.

In addition, use of transparent material as partitions across the floors which is further aided by added windows and skylights to maximizing daylight illuminance in the rest of the building.

As there were not sufficient illuminance specially on the middle block of the existing building.

Later with the design decision the illuminance in most of the building area is enhanced to the desired minimum illuminance of 300 lux for general office work requirement.

1

Section

2

3

4

5

4

Section

5

6

6

Life cycle assessment of design structure

Step 2

Improve solar access and internal heat gain

Step 1 Retain major structural elements

Step 3

Step 4

Reuse maximum existing components

Only necessary additions to repurpose as per the brief

Step 5

Low emissions materials and offset with on-site generation

What is included in the LCA calculations for this project is only the new components added to the building. That means none of the existing components are considered for the analysis of the proposal. The existing building is thought to have lived its’ lifetime of 60 years and therefore the emissions from the initial building should not be accounted for again. For the new components, a full life cycle assessment has been made (stages A to C/D). The parameter that LCA is being used to find is the Global Warming Potential (GWP) measured in CO2eq.

Exterior System + other

Walls Ceiling Floors Finishes Doors Furniture

Interior

• • • • • •

Structure

• Foundation • Beams • Column

• • • • • •

• • • • • • •

*EXCLUDED

Wall Roof Windows Glazing Doors Landscaping

Mechanical Electrical Plumbing Speciality Staircase Elevator Others

Inventory Analysis:

Some parts are excluded as a result of lack of defining information, lesser impact or due to lack of adequate detailing in the current design stage, so as to avoid misleading results (such as for the building systems).

Insulated windows

Roof

Third floor

Atrium with glass panels walls Second floor

CLT deck and connecting bridge Insulated timber frames walls

First floor

Better insulated windows

Inventory Analysis:

Atrium with ETFE roof

S.no

Building materials

Area (m2)

1.1

Glass curtain wall

1589

Interior wall finish

2663.4

1.2

Glasswool insulation interior (λ=0,0038)

Building materials

Area (m2)

Glass door

125

Wooden door

247

166.1

Workshop

19

Volume (m3)

33.27

S.no

4

Volume (m3)

Construction wood (stud for interior wall)

567.5

9.7

Double glazed window SW wall

61

Glasswool insulation exterior (λ=0,0031)

1414

212.1

Double glazed window SE wall

63

Wood Exterior cladding

35.35

Double glazed window NE wall

43

I‐bjelke (stud for exterior walls)

12.86

Double glazed window NW wall

338

1.4

Concrete walls

38

Sum double glazed window

505

1.5

Glass curtain wall

1589

Skylight windows

145

2.1

ETFE

561

123.42

Sum windows

650

3.46

Ramps (t = 200)

69

13.8

Staircase (t = 250)

140.75

35.187

1.3

Column, gluelam CLT slab (t = 220mm)

561

5

123.42

3.1

6 Beam, gluelam

4.61

Ramp & Staircase railing (t = 25mm)

31

Wood flooring

11.6

Railing, aluminium tube

66

S.no

Building materials

Area (m2)

7

PV panels on roof

1460

8.1

Leca blocks, t = 200mm (reuse)

389

8.2

Old windows (reuse)

374

Volume (m3)

77.8

S.no

8.3

Building materials

Area (m2)

Volume (m3)

Roof panels (reuse)

800

4

M2 extra wall panel (reuse)

502.9

2.5145

M2 extra wall panel (reuse)

424.79

2.12

Insulation comparison : Woodfibre V/S Glasswool (U-value is calculated with 200mm of concrete masonry and the insulation) S.no

Insulation Type

Unit

Thickness (mm)

λ –value (W/Mk)

U –value (W/m2K)

U -value requirement

GWP (khCO2e/m2)

1

Woodfibre

1 m2

198

0.0038

0.18

< 0.22

3.10

2

Glasswool economy

1 m2

198

0.0038

0.18

< 0.22

1.90

3

Glava extern 31

1 m2

148

0.0031

0.2

< 0.22

0.85

Glazing comparison : Glass V/S ETFE (Achieved U-value for 4 layer ETFE glazing as opposed to the more normal 3-layer ETFE) U-value

Solar heat gain

Solar admittance

area

Area unit

Lifespan

GWP (A-C Stage)

GWP (A-D stage)

NorDan

1.2

52%

72%

1.00

M2

40 years

125.49

124.83

ETFE

1.9

75%

90%

1.00

M2

50 years

62.78

15.47

Interior wall type (Including 100mm mineral wool insulation and plasterboard 13mm on both sides)

Wood frame for exterior wall: Normal timber frame V/S I-Beam

Interior wall type

GWP (kgCO2e/m2)

Added construction

U/Value with 200mm masonry

Weight of added construction

CLT interior wall

19

Insulation + I – Beam

0.188 W/M2k

8.9 kg/m2

Wooden stud internal wall

13

Insulation + Spruce

0.200 W/M3k

10.0 Kg/m2

Design LCA Results :

Total embodied emissions by building component

Generally the materials with the lowest greenhouse gas emissions were chosen for the added materials to the project. In this way, all the major parts that add to the material emissions of the project have had a preliminary material comparison analysis, on the previous page.

Total embodied emissions by resource type

The biggest contributors to GHG emissions are the internal walls and non-bearing structures. This is due to the large glass walls that are added to the atrium. Glass provides a glazed surface that is translucent, gives daylight to the inside of the building while thermally separating the semi-conditioned atrium space from the conditioned areas.

Operational Emission (energy use of building) The atriums led to a significant improvement in operative temperatures compared to the existing structure, with a small drop in energy needs. But by adding insulation to the exterior walls, the energy demand dropped three folds (from 73kWh/sqm to 25kWh/sqm).

For calculation TEK17 energy requirement standards for an old structure, with chance if leakage and cold bridges due to incremental construction type are considered. Heat pump is used for the heating purpose of the building, as it has favorable system efficiency, which reduces the operational energy use.

End use

Energy demand kWh/m2

Thermal energy need

70

Electric energy need

24

m2

4381

5227

TOTAL

Since the ventilation system choosen is air to air heat pump, balance ventilation with heat recovery, by using a heat exchanger is used.. Thus we avoid adding two separate systems (one for ventilation and one for heating) and reduce the need for structural changes as well as reduce adding more technical equipment into the project. The operational energy use of the building has been calculated using typical values for office spaces in new buildings, following the current building code, multiplied by m2 of used space.

Supply system kWh/yr

306670

125448

Name

Coverage

Delivered energy Efficiency

kWh/yr

khCO2/kWh

kgCO2/yr

year

kgCO2/60yr

Heat pump (air to air)

80%

2.16

113581

0.130

14766

60

885936

Electric boiler

20%

0.88

69698

0.130

9061

60

543642

Direct electric

100%

1.00

125448

0.130

16308

60

978494

40135

60

2408072

308727

Energy need and emissions

Emissions

Balance and Compensation of GHG emission Since this is a refurbishment project, the emissions connected to energy use become a much bigger factor than in new constructions.

This is because in this project it has been added relatively few materials. To offset the operational emissions, PV panels have been added to the roof. The PV energy analysis made in Revit show coverage 74% building’s energy need. This is obtained from 1460m2 PV panels installation over the roof.

PV panels placement on roof

PV panels

kWh/yr

kgCO2e/kWh

kgCO2e/yr

Energy generation capacity

228643

-0.13

-29724

Total energy need

308727

0.13

40135

Need from grid

80084

0.13

10411

Emission offset from on-site energy generation

The PV-panels both decrease the emissions by generating local renewable energy, also contribute with material emissions. The material emissions contribution for PV panels is quite high, partly due to their short life expectancy of 20 years. The material emissions are not added to the scope of assessment of the main life-cycle analysis but a secondary analysis was made to see the impact added from the PV-panels. The results show an almost 2,5 times increase of the total GHG emissions, the results show that the biggest contributor from material GHG emissions comes from PV-panels.

Embodied emission by life-cycle stages

Total emission from new construction when PV panels are added to LCA calculatiom

Comparative analysis

Benchmark result for the scenario of the existing building being built today

The comparative analysis is made to see the advantages of renovating instead of building new construction, from an emission perspective. The reason for this high emission in the existing building can possibly be due to limitation of technology (as parts of the building are quite old), lack of a sustainable approach to design as well as carbon-intensive construction materials such as steel and concrete that have been used extensively for heavy construction.

Benchmark results for the renovation scenario of the Old structure

The proposed design tries to minimizing emissions as a core criteria for choice of design interventions and materials. Another major factor is reuse of the existing structure, which helps significantly reduce emissions making adaptive reuse a solid strategy to keep the overall emissions due to new construction low. The numerical results for the total GHG emissions reveal that renovating the building would lead to only 7% of the emissions compared to the new construction scenario. That is an incredible 93% decrease of emissions in deciding to keep and reuse the existing L&S building.

Even if reducing GHG emissions was the main design driver of the project there is a balance to be made between emission reducing decisions and design decisions. The thought process between this balance is that a good design will attract more people and create a lively and productive space for the community. The more people, life and activities the project building will accommodate in the future, the more function it will give to the building itself. With this thought process in mind one can argue that even the most sustainable building isn’t sustainable if it doesn’t get used.

In this report, the main measure of emissions has been presented as kgCO2e/m2. The measure is the most commonly used to compare the sustainability of a building in regard to GHG emissions. Still one problem with measuring emissions up against square meters of space doesn’t take into account the usability of the space. Another measure that can be used in projects for example is to look at kgCO2e/person for example in the open office area. During the assessment of the existing building there have been a number of difficult things to know. It has been difficult to know which materials are fit for further use or that must be changed out.

Example is the windows, the roof, interior finishes etc. A large part of this problem is due to lack of information. Working with existing buildings is complicated and a big part of the work is dependent on being able to inspect the project building. Since, the building study from inside was not allowed, a lot of assumption have be made throughout about the spaces and material of the construction from the available photographs.

Conclusion and Discussion :

The study conclusion is that reuse of a building is better than demolishing and building new, in terms of GHG emissions. The goal of this project has been looking at LCA not only like an end result but implementing it throughout each design and technical decision for the project. From the initial design sketches to lowering the buildings energy need and choosing more sustainable materials.

RENOVATION + PV

17.3%

NEW CONSTRUCTION

100%

RENOVATION

7%

THANK YOU !

Divya Naik (divyanai@stud.ntnu.no)