Eco-station brochure

Eco-station & Exhibition House

Exhibition House The Exhibition House demonstrates passive design solutions and different technologies to enable low-carbon living.

The Eco-station and Exhibition House are on Camp Road, Bordon, Hants, GU35 0LH. As we only have pre-booked disabled parking on site please consider walking, cycling or using public transport to get there. For more information on travelling to the Eco-station please see www.whitehillbordon.com

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Super insulation Rainwater harvesting A winter garden A trombÊ wall A solar roof Inter-seasonal heat store This document has been written on behalf of the Whitehill & Bordon Eco-town team and was designed by East Hampshire District Council’s Communications Team.

Ecostation

The Eco-station demonstrates how a redundant building can be brought back to life to serve a new purpose – as well as being refurbished to reduce its carbon footprint.

The building was built in 1906 and was used as a Ministry of Defence fire station. It will now serve as a hub for the Eco-town.

The Eco-station now has an interactive and fun exhibition, a lecture room, an activity room and office space. It will also house the Woolmer Forest Heritage Society’s collection.

The refurbishment has: > Reduced carbon emissions by 40% > Reduced the energy consumption required to heat

the building by 50%

As the work to make the building more energy-efficient took place the majority of site waste was either recycled, reclaimed or sold locally.

Some of the energy-efficiency measures included: > insulating floors in the exhibition space, lecture room and south wing > cavity wall insulation throughout the building > insulation to inner face of external walls in former appliance bay and lecture room > roof insulation > passive stack ventilation to the lecture room (this is a system to suck air out of the building so that it is ventilated.

Using a passive system saves energy and costs associated with a mechanical system) > new energy-efficient lighting and heating controls to improve energy-efficiency > new gas condensing boilers > double glazing to former appliance bay opening The following companies were involved: BBM Sustainable Design (architects) BBP Engineers (structural engineers) Boulter Mossman (contract design management coordinators) Chris Blandford Associates (landscape architects) FT Allen (quantity surveyors) Robinson Associates (mechanical and electrical engineers) SRE (BREEAM assessors)

Exhibition House The house has been designed to work as an exhibit – and in the future will be a family home.

The Exhibition House meets the Code for Sustainable Homes (level five).

It has been designed to reduce energy consumption so that no conventional central heating system is needed. Instead photovoltaic panels, solar thermal panels and a mechanical ventilation and heat recovery unit have been installed alongside passive design features such as the trombé wall and winter garden.

> Rainwater harvesting

> Insulated roof and floor

The rainwater harvesting system collects rainwater from the roof and uses it to flush the toilets

Concrete is one of the most energy intensive construction materials and has a very high carbon footprint. The floors and foundations were designed to minimise its use.

Instead, compacted hardcore and reinforced screed have been used.

The system does not need a pump and uses no electricity.

It makes the whole house use far less water than an average new house.

Cork is a very sustainable floor finish and has been used here. It can be harvested from the same tree for up to 200 years. Trees don’t need to be cut down to produce cork and the material is easy and cheap to maintain.

Heat will be gathered from the kitchen and bathroom and redistributed to the living spaces during the day and into the evening.

The north side of the roof is clad in cedar tiles known as ‘shakes’, a sustainable, durable material. The south side is almost entirely covered in photovoltaic (solar) and solar thermal panels.

Photovoltaic panels produce electricity and solar thermal panels produce hot water.

Some of its features include:

The weathering layer beneath the solar panels is made of a waterproof bitumen membrane. This material is recyclable and was supplied by the first company in Europe to set up a recycling plant to reuse this material.

> Inter-seasonal heat store

> Trombé wall

The inter-seasonal heat store is designed to store hot water during the summer for use in winter.

The store is a large, insulated, underground tank holding 9,000 litres of water. It is buried underground both because of the space it needs and also because the warmth of the soil (its ‘geothermal energy’) helps to keep the water warm throughout the year.

This heat store provides top-up heating in two ways: 1. Additional warmth to heat the house during the coldest months of the year.

2. Additional heat to help the solar thermal panels make hot water in the winter.

The floors upstairs are constructed from timber joists, but with a 50mm floor finish on top to help increase thermal mass, to reduce changes in temperature and protect against summer overheating.

> A winter garden This south-facing area – a ‘winter garden’, helps to heat the house in winter and allows for flexible changes in the way space is used at other times of year.

In winter, both the inner and outer doors are kept closed to act as a buffer zone to the cold outside. Any heat from the low sun is trapped and transferred inside to help warm the rest of the house.

In summer the outer doors are left open, creating more space for outdoor living. In spring and autumn the inner doors are opened, creating more internal living area.

> Mechanical ventilation unit with heat recovery The house is extremely airtight and has very high levels of insulation.

However, some air circulation is needed to air the rooms and to allow the house to breathe.

To help air to circulate, a ventilation and heat recovery system has been installed that circulates fresh air and extracts stale air throughout the house. It re-uses heat from the stale air, from the bathroom and kitchen, to warm up the fresh air being drawn in.

The mechanical ventilation unit pump uses a very small amount of electricity, which is offset by photovoltaic (solar) panels on the roof. If more heat is needed, it can be taken from a special hot water tank known as an inter-seasonal heat store in addition to the hot water tank in the house.

Cold incoming air is also pre-warmed by an awaduct – this is a large tube embedded in the ground which will reduce some of the extremes of the incoming air temperature.

During really hot weather, the windows should be kept closed whilst the system runs in reverse, cooling the warm air as it comes in from the outside.

> A winter garden This south-facing area – a ‘winter garden’, helps to heat the house in winter and allows for flexible changes in the way space is used at other times of year.

In winter, both the inner and outer doors are kept closed to act as a buffer zone to the cold outside. Any heat from the low sun is trapped and transferred inside to help warm the rest of the house.

In summer the outer doors are left open, creating more space for outdoor living. In spring and autumn the inner doors are opened, creating more internal living area.

> Super insulation The house is super insulated to dramatically reduce its heat loss. In fact, the heat produced by people living here, and captured from the sun, will keep the house warm all year round. This means the house does not need any central heating.

The insulating properties of things like walls and windows is measured in units known as ‘U-values’. The lower the U-value, the better it is at retaining heat.

These walls are insulated with recycled newspaper. Their U-value is 0.08, which means they are incredibly efficient at keeping heat in. By contrast, the walls of a standard new brick-built house have a U-value of around 0.35. A standard existing home built 20 to 30 years ago has a U-value of around 1.

The south facing ‘trombé wall’ is designed to trap and store heat from the sun and slowly release it towards the interior, especially during the winter and at night. The idea was developed in the 1960s by the engineer Felix Trombé and the architect Jacques Michel.

The design of the Exhibition House makes the most of the low-angled winter sun, because the wall will catch any heat and radiate it inside the house over many hours, keeping the living spaces cosy after the sun goes down. The time lag between trapping the heat and releasing it means the house stays warmer for longer.

This wall is made from a mixture of traditional and space-age technology, and is a sandwich of four layers: 1. An outer screen of coppiced sweet chestnut deflects solar radiation during the warmer months whilst letting it penetrate at colder times.

2. A layer of polycarbonate and nano-gel absorbs solar energy but stops any re-radiated energy from escaping. The nano-gel insulation is very thin but is a superb insulator.

3. A sealed air gap helps to improve the insulating properties.

4. A 200mm wall of unfired clay blocks with a clay plaster finish radiates the trapped heat into the rooms.

Other features of the Exhibition House include: > The timber frame for the house and the roof structure were manufactured off-site so that they benefit from a controlled factory environment and reduce site waste > The sweet chestnut timber cladding demonstrates how even the external fabric can contribute to creating a low-carbon building. This timber has been harvested from local coppiced wood and the latest joinery technologies have been used to produce an economically-viable product The following will soon be part of the house: > The eaves of the house will have nesting space for swallows and swifts. Native species will be used for hedging and there will also be a pond. The garden has been designed to include raised beds, composting bins and a large capacity rainwater butt > Grow-your-own food will be promoted with a range of edible plants and fruit trees and an organic allotment and herb garden The Exhibition House was designed by Riches Hawley Mikhail Architects with BBM Sustainable Design.