Stoneguard C60, Nottingham University

An interesting example is being developed at Nottingham University, where they are currently constructing an ecologically-friendly prototype four-bed three-storey (including basement) house of the not-so-distant future (see picture). One of their aims is to show how sustainable energy technologies developed around the world can be combined with modern construction methods to make energy-efficient, cost effective homes which are easy to build. Some of the technologies and construction being used include:

• the first British domestic use of a wax board that boosts thermal mass and absorbs heat keeping a room cooler;
• the use of triple glazing, electrically operated integral blinds and external solar shading louvers;
• a main structure of a light gauge steel frame produced in off-site modular panels with external insulation sealed to reduce fabric and ventilation heat losses. The U-values will far exceed the Building Regulation requirements;
• an integrated conservatory/sunspace;
• a ground cooling/heating system which thermally conditions air that goes into the sunspace by passing it through earth tubes which preheats air in winter and cools it in summer;
• the use of a micro wind turbine;
• a ventilation and heat recovery unit that converts thermal energy from solar panels to produce hot water, hot air for space heating, heat recovery, air cooling and ventilation;
• advanced wireless heating controls that connect to weather stations for forecasts;
• a water management system which collects and cleans bath and shower water as well as rainwater for reuse to flush toilets which can reduce water consumption by up to 30%;

The construction of the house is expected to take 8 weeks. Information about the project is available online.

This house is part of a larger project that will include another five demonstration homes, each with a different theme. All of these homes will be inhabited and monitored to assess their performance.

Sustainable Housing

from Welsh Housing Quarterly, Issue 65 - Jan 2007
Following on from the features in the last issue of WHQ, David Rowley provides a practical guide to sustainable housing.

Introduction

The Government has committed to reducing carbon dioxide emissions by 20% of the 1990 levels by 2010 and 50% of the 1990 levels by 2050 and this is now being reflected in regulatory pressures.

There is a great need to encourage improvements in the existing housing stock. This article highlights the main requirements and assessment tools available for housing, comments on the costing issues, refers to case studies and lists sources of further information. It also refers to studies that help disprove the argument that the cost of building more sustainable homes is prohibitively expensive.

Environmental Assessment Tools and Performance Requirements

For large sites or estates:
There are few mechanisms for assessing the overall sustainability of a combination of buildings and infrastructure such as in housing estates or urban villages. However, the Building Research Establishment (BRE) has produced A sustainability checklist for developments: a common framework for developers and local authorities which provides practical tools and indicators to measure various sustainability criteria. This checklist needs to be adapted for each site to reflect local differences. Information is available online

For buildings:
EcoHomes is a methodology for rating the environmental sustainability of buildings, on a scale of ‘pass’, ‘good’, ‘very good’ and ‘excellent ’ and covers houses as well as apartment buildings, new and renovated homes. Other types of accommodation, such as sheltered homes or student flats, can be assessed using a bespoke version of EcoHomes. It is available online

Topic headings assessed include energy, transport, pollution, materials, water, ecology and land use and health and well-being.

English Partnerships require ‘very good’ EcoHome scores for all schemes developed on their land and the Housing Corporation requires a ‘very good’ rating on any schemes they fund. The Welsh Assembly Government and some local authorities also set EcoHome standards as part of their planning requirements. Public sector contractors are usually required to achieve an excellent rating for all new buildings.

Renewable energy as part of planning conditions

About 90 councils now have policies requiring developments to achieve 10% of their predicted CO2 emissions through on-site renewable energy technology. The London plan is proposing increasing this to 20% and other councils may follow suit.

Planning policy document PPS22 This document allows English authorities to adopt policies such as the one above. A companion guide to this provides guidance, case studies and some technical information on renewable technologies. Code for Sustainable Homes. This assessment methodology, currently in draft form, is the result of a Sustainable Buildings Task Group.

Building Regulations

Part L 2006. This regulation on conservation of fuel and power was recently revised, came into force in April 2006 and now requires CO2 emission targets, rather than U-values for new builds. The regulation is in four parts, two are for new and existing dwellings.

Estimates of the effect on construction costs vary from 1.9% upwards. Building Regulations Part F 2006. This document on ventilation has been revised to bring it into line with Part L. SAP 2005. This is a calculation tool used for assessing whether a dwelling complies with Part L1a 2006 or not.The BRE’s Green Guide to Housing Specification is closely linked to EcoHomes and provides guidance to designers and specifiers on the environmental impacts of the main fabric elements commonly used in housing. The guide is currently being updated and a new online version is expected to have been published around the time that this issue of WHQ is published.

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