Hanham Hall homes performance evaluation

[edit] Introduction

Hanham Hall is a development of 185 new homes located in South Gloucestershire. All new homes were constructed by Barratt Homes to comply with the Zero Carbon Homes definition. BSRIA was employed to assess the performance of the properties in-use for energy and water consumption, construction quality, indoor environment and to collect the occupants’ opinions on their new homes.

[edit] Process

[edit] Design and standards review

Construction of the homes started on site in 2012 and was completed in early 2016. The design details and energy strategy were reviewed at an early stage. BSRIA reviewed the design brief and SAP predictions, which were used for comparison to monitored data.

[edit] Handover information and home-use manuals

BSRIA collected and reviewed all information handed by the developer to the new home occupants. In addition, researchers participated in new home tours provided to residents by the developer’s team.

[edit] Occupants' satisfaction surveys

Information on site demographics, levels of occupancy in the different properties, and occupants’ levels of satisfaction with their new homes was collected through occupant surveys developed by BSRIA.

[edit] Monitoring energy, water and indoor conditions

Post-occupancy energy and water consumption of all properties was monitored for three years by BSRIA researchers, using wireless sensors which recorded data at five-minute intervals.

A sample of ten properties was reviewed in detail including energy-use patterns, performance of installed services and indoor conditions (IAQ and thermal comfort). In addition, BSRIA performed post-occupancy airtightness tests, thermographic imaging and in-situ U-value measurements to assess the quality of the fabric in the homes.

[edit] Results

[edit] Occupant Satisfaction

Responses indicated that the majority of residents were very satisfied with the performance of their properties. Overall, the respondents reported that their heating, electricity and water bills were much lower compared to bills in their previous homes.

[edit] Energy and water performance

The Hanham Hall houses consumed on average 5500 kWh of gas per year, indicating a high level of energy efficiency. Average regulated and unregulated electricity consumed across the site was less than predicted by SAP models.

Occupants consumed less than 80 litres of water per person per day, meeting the Code for Sustainable Homes* Level 6 target for water consumption.

(* Following the technical housing standards review, the government withdrew the code for sustainable homes, in 2015. Elements of it are still used for the evaluation of sustainable homes.)

[edit] Indoor conditions

CO2 levels monitored in a sample of ten properties indicated good ventilation rates for all the different design typologies.

Thermal conditions within the sample properties showed comfortable temperatures maintained throughout the year with no overheating.

[edit] Installed services

MVHR units installed in the properties consumed similar levels of electricity to that predicted, with no indication of any operational issues.

PV panels generated similar amounts of electricity to that predicted, which accounted for almost 25% of annual electricity demand in monitored properties.

[edit] Notes and considerations

• The handover process review indicated the need for improvement. Findings identified a complex presentation of content, and a lack of information relating to the long-term maintenance and operation of the properties.
• Some occupants found operating their heating systems challenging, reporting that controls could be simpler and easier to understand.
• Even though gas consumption of the properties was low, it was 40-60% higher than SAP predictions. Although used for comparison purposes in the study, SAP predictions do not accurately predict in-use energy consumption.
• Airtightness tests conducted on four properties three years after construction, indicated a deterioration from the initial tests which were less than 1.5 m3/m2h @ 50 Pa. All results were less than 3m3/m2h @ 50 Pa.

The research programme provided Barratt Homes with a unique insight into the performance and quality of its new home designs.

[edit] About this article

This article was written by BSRIA in conjunction with Barratt Homes. It was previously published on the BSRIA website and can be accessed HERE under 'homes performance evaluation'.

More articles by BSRIA on Designing Buildings Wiki can be found HERE.

[edit] Related articles on Designing Buildings Wiki

• Approved documents.
• Building Regulations.
• BREEAM.
• Consequential improvements.
• Dwelling Emission Rates.
• Earthship.
• Eco town.
• Energy certificates.
• Green deal.
• Home Quality Mark.
• Leadership in Energy and Environmental Design.
• Lifetime homes.
• Lifetime neighbourhoods.
• Nationally described space standard.
• NHBC technical standards.
• Passivhaus.
• Roof insulation.
• Ska rating.
• Sustainability.
• Sustainable Urban Drainage Systems.
• U-values.
• Zero carbon homes.

--BSRIA