Ryedene shortlisted for Essex Housing Awards

Ryedene has been shortlisted in the #EssexHousingAwards category ‘Climate Action – Low / Zero Carbon in New Homes’! The scheme is a new-build Passivhaus development comprising of a three-storey block of nine flats, with associated parking and improvement to the adjacent open space.

Basildon Council aim to reduce the operational and embodied carbon emissions from their social housing stock. The design team were charged with a ‘fabric first’ approach, based on the specification of high levels of insulation, triple-glazed windows, and minimising thermal bridges in the construction to achieve the Passivhaus standard. Attaining this standard is monitored through the design phase using the Passive House Planning Package (PHPP), building energy modelling software, and by rigorous oversight and airtightness testing during construction.

To minimise energy use orientation and form factor were considered from the outset, with the internal layout designed to enhance winter solar gains, whilst preventing overheating in summer. Iterative TM59 assessment was used to develop a smart façade including low g-value glazing and brise soleil elements that provide essential contribution to the building’s performance, are contemporary in aesthetic and ensure compliance with Part O and F of the Building Regulations. Ahead of tender, the frequency of overheating noted on the PHPP 3%, well below the threshold target. This ensures the homes are adapted to mitigate future overheating risk.

Embodied carbon life cycle assessment for Product Stage (A1-A3) was undertaken in developing the structural schematic, providing a kgCO2e/m2 options appraisal to ensure the chosen strategy provided the least amount of embodied CO2, balanced with cost efficiency. Consequently, Structural Insulated Panels (SIPs) were used to maximise the airtightness of the building, limit construction defects and waste, and reduce the delivery programme by using factory-made elements which are more accurate than on-site cut timber frames.

The thermal performance of SIPs panels along with 120mm high performing insulation secured an external wall U-Value of 0.10W/m2K meeting the Passivhaus criteria and ensuring warm, comfortable homes.

Demand of heat, ventilation and domestic hot water is supplied by Exhaust Air Heat Pumps, with minimal addition of electric radiators, simplifying service layouts to allow for easy operation by the residents. The combination of these systems with the low energy demand of the building mean the homes will be fossil fuel free, but also very affordable to run. The roof pitches maximise the opportunity for photovoltaic (PV) panels, providing the site with renewable energy that can contribute to each property’s energy demand. Overall energy use and carbon emissions are minimised, with a Heat Demand of 11kWh/(m2a), and total carbon emissions of only 0.4 tonnes CO2e/year per home, compared to a UK average of 8.1 tonnes.

The new flats are seamlessly integrated within the surrounding open space. Whilst developed on existing green space, additional trees and soft landscaping enrich biodiversity on site and provide varied new habitats for local wildlife.

For Basildon Council, this scheme has been an important pilot, to demonstrate high-performing, fabric first buildings can serve the public sector effectively. Despite rising inflation and increasing material costs that have challenged the sector in its entirety, the commitment to the new residents has been a driving ambition, to deliver well insulated, comfortable and cost-effective homes for the community. For the Council, this is just the beginning.

Ryedene Team:

Architects: ECD Architects
Employers Agent: Keegans
Structural Engineers: Simple Works
Building Services: Ridge and Partners
Landscape Architects: OHLA
Visualisation: Karashetskyy Architects

For further information on Essex Design Awards shortlisting, please see this link: Essex-Housing-Awards-2023-Shortlisted-Announced.pdf (housingessex.org)