Sustainable Self‑Build Advisor

Use continuous insulation, correct cavity closers, and thermally broken connections. Thermal bridges lower real‑world performance and invite condensation.

Request airtightness targets, blower‑door tests, duct leakage tests and photos at key stages. Performance is won or lost on site.

In efficient homes, space heating and hot water dominate energy bills. Prioritise fabric improvements, efficient heating systems, and renewable energy over complex controls.

Consider embodied and operational carbon together. Choose low‑carbon materials, renewable energy, and design for longevity. Plan for future decarbonisation of heat and electricity.

ASHP efficiency improves with lower flow temperatures. Use larger emitters, good controls with weather compensation, and ensure adequate clearances around outdoor unit for airflow.

Warm roofs place insulation above the structure, reducing thermal bridging risk. Ensure continuous air and vapour barrier and adequate fall for drainage.

Large unshaded glazing can overheat in summer and lose heat in winter. Target high‑performance frames, low‑psi installations, and use lower g‑value glass on sun‑exposed elevations.

Push for ≤3 ACH@50 (or better) with a continuous airtight layer, tapes and gaskets. This cuts heat loss and improves comfort. It also enables efficient low‑temperature heating and MVHR.

Timber‑based systems store carbon and typically have lower embodied impacts than dense block or ICF. If acoustics/thermal mass are concerns, pair timber with a limecrete slab or internal masonry feature walls.

Small PV systems (1‑3kWp) should prioritise daytime self‑consumption. Use smart controls for water heating, consider battery storage for evening loads, and choose efficient appliances.

Basic double glazing can perform well with good frames and installation. Use low‑E coatings, argon fill and thermally broken frames. Pay attention to reveals and sill insulation.

Mineral wool should be cut slightly oversized and friction‑fitted without compression or gaps. Use membranes for wind‑tightness and ensure continuous coverage around services.

Simple, compact shapes lose less heat and are cheaper to make airtight. Complexity increases cost, risk and bridging.

PV offsets grid electricity. Tilt/orient for annual yield and consider a modest battery only if you have high evening loads or dynamic tariffs.

Fixed overhangs, shutters or external blinds block summer sun while keeping views and ventilation. Planting (deciduous trees) can provide seasonal shading too.

Cylinders provide good flow rates and can use off‑peak electricity. Size for daily demand plus 25% margin, insulate well, and consider solar coil pre‑heating or heat pump integration.

Achieving 3‑5 ACH@50 requires consistent detailing. Use standard airtightness details, train trades, and test early to catch problems before finishes go on.

Concrete slabs provide good thermal mass but need edge insulation to prevent thermal bridging. Consider under‑slab insulation thickness vs heating load and screed compatibility with UFH.

High cement content drives embodied carbon. Specify cement substitutes (GGBS/PFA) where appropriate and ensure robust thermal breaks.

Hot water is a big share of energy in efficient homes. A heat‑pump cylinder or well‑designed solar thermal can cut demand substantially.

VOCs from paints, adhesives and furnishings affect indoor air quality. Choose water‑based paints, formaldehyde‑free boards, and natural finishes. Allow curing time before occupation.

Low‑flow taps and showers can halve water consumption without compromising user experience. Choose aerated or laminar flow types and ensure adequate pressure for thermostatic mixers.

Natural ventilation works through pressure differences and buoyancy. Design openings on opposite sides, use high‑level outlets for stack effect, and avoid single‑sided rooms.

If you don’t have MVHR with summer bypass, design openings for night purge and cross‑flow. Ceiling fans add big comfort for tiny energy.

Healthy interiors matter. Low‑VOC paints and adhesives, plus reused or locally sourced materials, reduce impacts and can add character.

To cut potable water use and sewer loads, use low‑flow taps/showers and consider a simple RWH system for WCs, outside taps and washing machines.