Case Study: Code for Sustainable Homes Level 5 House

Short Description

Overview The construction of the house will achieve Level 5 of the Code for Sustainable Homes. Lessons learned will feed into other Code compliant schemes in our development programme.

It is a demonstration house but it has a relatively traditional appearance and importantly will be lived in. Official demonstration status has also been obtained from the Housing Forum and we have been sharing lessons learned so far with other Housing Forum members from across the country and even the New Zealand Government has shown interest.

Any feedback from the resident in terms of the comfort and experience of living in the house will be important. Energy bills will be considerably lower and the relative carbon footprint of the house will also be very low

Key Elements

Thermal Insulation

Thermal bridges to Energy Saving Trust recommended standards, U-values in line with Passivhaus standards, highly insulated thin bed blockwork used for speed of construction.

Air Tightness

In line with Passivhaus standards.

Windows and Shading

Window glazing (triple paned, low-emissivity coating, gas filled), timber window frames.

Ventilation

Mechanical ventilation with heat recovery.

Heating and Hot Water

Ground source heat pump and underfloor heating, boosted by solar thermal tiles.

Cooling

Investigating ground source cooling.

Solar Thermal

Solar thermal tile system (roof integrated) for production of domestic hot water monitored to check if excess could be used to replenish geothermal heat for the ground source heat pump.

Solar Photovoltaic

Photovoltaic tiles in place of roof tiles and passive solar shading.

Other Renewables

Ground source heat pump.

Electricity Saving Products

Energy efficient lighting systems, energy efficient appliances (fridges, dishwashers etc.), smart energy monitors.

Water Saving

Water-efficient appliances and fittings, rainwater harvesting (monitored).

Capacity Building

Training staff – professionals / organisation and management staff / technicians / energy experts / social workers / caretakers/ technicians of building company or other key stakeholders

Certification

Air pressure testing, thermographic imaging, energy performance certification. PHPP referred to

Project Management

Green sourcing and selecting products/materials using vetted by ‘One Planet Products’, quality control (monitoring performance of technologies/ monitoring quality of services)

Work with Residents

Providing very good dwelling manual, organising workshops, site visits together with community members, face-to-face field meetings or interviews, working with residents to monitor use

Raising awareness of energy saving through campaigns, posters, etc., training programmes for residents, involving residents in the design process, ‘One Planet Living’ principles encouraged

Main Results

No outcomes as yet.

Lessons learned

- Originally aimed at Level 6 of the Code but it requires estimated carbon emissions produced by the use of cooking and appliances to be covered by renewable energy as well as heating and hot water, lighting, pumps and fans whereas Level 5 only requires emissions from heating, hot water, lighting, pumps and fans to be covered. Covering the extra appliance and cooking use for Level 6 increases costs significantly and adds extra practical difficulty for small projects.

- Reaching Level 6 especially for one house cannot be achieved using heat pump technology without a vast amount of PV solar technology. If doing so then a mono pitched roof is the only way to get enough roof space and / or a remote on site PV array situated in the garden could be used.

- Biomass is a good technology if it is used in the right circumstances and there is space to deliver and store the fuel and also position the boiler. Communal biomass heating for schemes of 20 units plus is more viable.

- Ventilation - assume that a high specification ventilation system will be required and plan this in at the design stage as it is a lot easier to leave it out than add it in once plans have been approved.

- Obtain as much information up front as possible including risks such as flood risk, water runoff calculations and soakage tests, quality and capacity of local drains and ecological risks.

-Set clear, early targets to enable good design solutions which will possibly save unnecessary extra expense and hardship later on and to ensure the buildings are success.

Additional Information

This scheme is deliberately designed to look relatively ‘normal’ for English housing due to the need to fit into an existing context and obtain planning permission – therefore it relates better to our existing stock and elements can be used more easily to inform retrofit situations. Although it is a demonstration house it will be lived in and tenanted in the normal manner. Best practice in waste management during construction will also be employed using the WRAP toolkit.