Energy and Sustainability Consultancy to create Net Zero New Build Dwellings


Newport City Homes invited us to consult on the energy and sustainability of their St Johns Court development.  From early design team meetings, we decided we would aim for Net Zero Carbon Emissions on the new build dwellings and for a 75-80% Part L improvement on the change of use dwellings from the converted church.  To achieve these levels at early pre-application stage, we carried out SAP calculations on a sample of the dwelling types.  Giving up to 145% improvement over Dwelling Emission Rates (DER) would cover an approximation of the un-regulated energy which will be required to be offset in order to achieve Net-Zero Carbon Emissions.


From the original design we recommended several changes; new roof layouts, adjusted glazing sizes, increased floor to ceiling heights to accommodate MVHR, recessed balconies to mitigate overheating and Solar PV solutions to be integrated into walls, balconies, and roofs.  We were invited to consult on the Modern Methods of Construction (MMC), before choosing their timber frame supplier.  In addition to this we also consulted with the Mechanical Electrical designers and provided calculations, results, and specifications for the low to zero carbon technologies.


Our energy and sustainability strategy showed an adopted specification which demonstrates a 100-145% increase DER beyond the TER of Approved Document Part L1(2014) of the building regulations for Wales. Using a fabric first approach which goes beyond Passivehaus recommendations, we are predicting a 37% fabric improvement DFEE vs TFEE.  This pushes us past the new 2022 Part L1 requirements on fabric alone.  Passive measures through improved glazing and positioning, more efficient thermal mass and Passivehaus air permeability levels have also been adopted.


We have incorporated Waste Water Heat Recovery (WWHR) on all of the 2 and 3 storey dwellings, extracting the heat from the water the shower or bath sends down the drain. This heat is used to warm the incoming mains water, reducing the strain on the hot water demand and the energy required to heat the water up to temperature.


Using highly efficient Air Source Heat Pumps on every dwelling with Low Surface Temperature radiators or underfloor heating to allow a 35‚Äď45-degree Celsius flow and return temperature.¬†Air-to-water source heat pumps, transfer heat from the outside using compression to increase the heat at far greater efficiencies than using a boiler, heating the rooms via radiators or underfloor heating.¬† Using it in conjunction with a multi coil cylinder, also allows for efficient hot water and energy storage.


Ventilation will be managed by MVHR with anti-microorganism filtration. The mechanical extract ventilation takes the hot air from wet rooms and kitchens, passing it through the heat exchanges hermetically sealed unit, warming up the fresh air as a continuous supply into the living areas and bedrooms.


To complete our energy strategy, we will use Solar Photovoltaic throughout, more than double the required Solar PV is being specified to account for the unregulated energy usage (appliances and cooking).  We are exploring innovative placement of the panels as façade PV, balcony PV and the roofs have been redesigned to maximise Solar PV generation.


‚ÄúThis is a perfect example of what can be achieved with current technology available.¬† As is apparent, to meet Net Zero Carbon Emissions requires innovations from every direction, a combination of energy efficient technologies and a design team who all work together towards the same goal.‚ÄĚ

Carlos Melgar, Head of Energy and Sustainability


We work closely with you to provide energy and efficiency solutions to ensure that your construction project is sustainable as well as compliant and to the highest quality. Your project is our focus and we are ever-present to offer support and guidance from your very first contact with us.


Our energy consultancy services range from small extensions to large mixed-use and commercial developments. Our services include dedicated Consultancy Advice, Value Engineering, SAP Assessments and SBEM or Dynamic Simulation Modelling. Get in touch with us at or 01275 846995.


Cook Brown Energy is part of Hickton Group, Championing Excellence in the Built Environment.  Please visit our website to find more information about Building Control, Quality Site Inspections, Energy & Sustainability, Gas and Electrical Safety Management or Gas Auditing and Consultancy services.