Retrofit ethics

‘Clean, secure and affordable energy… available to all’1

Alongside sustainable new development, something must be done with the vast majority of buildings already standing, which people will still be occupying in 2050. While ‘eco-retrofit’ exemplar projects can be impressive, are there other ways to tackle the climate crisis without breaking the bank?

WORDS MARGARET REYNOLDS

Downing Place United Reformed Church insulated roof and daylighting on the new mezzanine ‘L ife is unfair,’ declared economist Milton Friedman. So it is with income – and with buildings. Many in this country are saddled with leaky, hard-to-heat or overheated premises, when we know it is possible to construct and renovate buildings to be comfortable and use minimal energy. ‘Retrofit’ is the term increasingly used for overhauling building fabric, ventilation, heating and electrical systems to reduce energy usage and the resultant carbon emissions. However, the present reality for clients who would like to eco-retrofit their property is the paucity of advice, funding and construction expertise that is available. Yet, building retrofit is absolutely critical for our future: ‘Do we really need to build, do we really need to put more carbon into construction, or can we upgrade our buildings?’ asks Peter Clegg, founding signatory of Architects Declare.2

An urgent need for retrofit

Construction has evolved empirically, by repeating what has worked in the past, but now we need it to absorb new research and technologies quickly. Remember the Green Deal in 2013? That was all about reducing the fuel used for heating, and cutting our utility bills in the process; Green Homes Grants were another problematic attempt. The goalposts keep moving; we are facing mass extinctions; the climate emergency demands massive cuts in carbon emissions; and the UK government target is to decarbonise energy for buildings and transport by 2030.3

An excellent new tool for implementing this reduction is Publicly Available Specification (PAS) 2035, which calculates the impact of retrofit, and safeguards clients’ interests and the quality of work (see page 11).

PAS 2035 Improvement Option Evaluations shows that some building geometries and retrofit designs achieve energy reductions more easily than others; some retrofit measures emerge as carbon neutral or better. PAS 2035 Medium-Term Improvement Plans indicate phasing opportunities and allow for future techniques and inventions.

This analysis allows us to face squarely the inevitable repositioning of retrofit goalposts. Of the 44 measures evaluated, 11 involve costly fabric insulation, but 23 are ventilation-heating or heat sources, and five are renewables. Not everything requires the six-figure construction costs of fabric measures, however important these are for increasing efficiency. Does our usual fabric-first priority make sense in an emergency?

Swapping gas heating for a heat pump can be minimally invasive and virtually eliminate emissions from fossil fuels. This is a real game-changer. With a heat pump, it is logical to seek off-peak, lower-carbon grid electricity at time-of-use tariffs, to generate power on the premises, and to store both these sources of energy in batteries. This points sensibly to a home energy system linked to an electric vehicle charger. Because the equipment bolts on, and supplier deals change, the kit can be easily accessed and updated as technologies evolve, rather than physically altering the building fabric.

We designers need to do continual research, leaving no stone unturned, yet hedging our bets. We need to prescribe retrofit procedures that can nimbly incorporate the inevitable changes of standards and technology as soon as they are proved.

How can we keep informed of the latest retrofit thinking?

Check out the achievements in Ireland under the Sustainable Energy Authority of Ireland (SEAI) in Passive House Plus magazine.4 If the work is overseen by a qualified project coordinator, 35%-40% of home retrofit costs are funded.

Manufacturers of the highest quality timber windows, doors, bespoke cabinet works and supplier of high performance aluminium doors and windows.

To estimate costs of retrofit measures, take a look at more than 50 homes available in our local Open Eco Homes (OEH) archive.5 Where disclosed in the OEH archive, overall retrofit costs run from £70,000 (DIY) to £280,000 (with a two-storey extension). Projects range from new architect-designed houses to DIY insulation work. Also included are three non-domestic buildings, and one narrowboat! Some OEH retrofit projects paid only 5% VAT for energysaving measures; some qualified for the government’s Renewable Heat Incentive (RHI, ends March 2022) for heat pumps – small, but useful, government subsidies.

Clearly, all our buildings need retrofitting and yet, illogically, for nondomestic buildings the government rescinded the 5% VAT reduction in 2013, and the tiny RHI non-domestic subsidy now offered is hardly worth the time it takes to apply.

Two large non-domestic retrofit projects in Cambridge city centre illustrate what can be done architecturally with interesting old buildings: As described in this issue, (see pages 7-9), the £12.8m retrofit of the

Entopia Building (2,986m2, £4287/ m2) to Passivhaus EnerPHit standard;

Architype, for the Cambridge Institute of

Sustainable Leadership.6 The £3.4m retrofit of Downing Place

United Reformed Church (990m2 , £3,414/m2), funded by the sale of another city-centre property; Archangel

Architects, completion April 2021.7

How should we advise clients seeking deep eco-retrofit?

Climate-activist owners who self-fund projects can show the way. Such projects boost expertise in the retrofit ‘market’ locally, generate publicity for procedures, the supply chain and contractors, and offer friendly access to their personal experience.

Similarly, with solar photovoltaic (PV) panels in 2010: ‘the rich’ with capital were offered high feed-intariff rates (extracted from all utility company customers) for expensive early installations. In the long run, however, this created a PV market with prices that were a third of the cost, benefiting everyone.

Designers wishing to develop their skills in retrofit have a number of options, including the six-month Association for Energy Conscious Building (AECB) CarbonLite course8 and courses by the Retrofit Academy.9 The AECB also offers retrofit coordinator training and Passive House Planning Package (PHPP) energy modelling.

In addition to design, we also need more skilled retrofit contractors. Few builders are ready to take on the costs in time and money of acquiring the necessary PAS credentials. Fortunately, funded retrofit training for builders is now firmly on the agenda of the Retrofit Academy. So, watch this space.

© M Reynolds RIBA New rooflights, solar shading and solar photovoltaics on the insulated roof at Downing Place United Reformed Church

© James Smith

© James Smith Because equipment bolts on, kit can be easily accessed and updated as technologies evolve, rather than physically altering the building fabric

External wall insulation may be suitable for some projects, but can require costly extension of roof eaves and verges, and drainage

Swapping gas heating for a heat pump can be minimally invasive and virtually eliminate emissions from fossil fuels Margaret Reynolds is an architect and retrofit coordinator, with experience of retrofit and residential projects across Cambridge. She is a member of the AECB and was energy adviser for the Downing Place United Reformed Church project.

References 1 www.cisl.cam.ac.uk/news/news-items/entopiabuilding 2 CFCI Cambridge Climate Emergency Month webinar – bit.ly/ca81declare 3 BEIS, The UK’s Nationally Determined Contribution under the Paris Agreement, BEIS, 12 December 2020, www.gov.uk/government/ publications/the-uks-nationally-determinedcontribution-communication-to-the-unfccc 4 Subscription included in AECB membership: www.aecb.net/benefits-of-aecb-membership 5 openecohomes.org/eco-homes-archive 6 www.cisl.cam.ac.uk/news/news-items/entopiabuilding 7 Archangel Architects www.archangelarchitects. co.uk/work/downing-place-united-reformedchurch-cambridge and CFCI Downing Place URC webinar – bit.ly/ca81downing 8 www.aecb.net/product/carbonlite-retrofittraining 9 www.retrofitacademy.org/coe

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