Plumbing & Heating for
New Builds & Extensions

Yes. We regularly work as a plumbing and heating subcontractor on projects ranging from single-storey kitchen extensions to small residential developments. We can work to a builder's programme, attend site meetings, and provide all necessary certificates and commissioning documentation. We communicate proactively with the main contractor and flag any programme impacts early.

We issue Gas Safe installation certificates for all gas work, Building Regulations Part L compliance documentation for the heating system, and Part G compliance for hot water systems. Where a boiler manufacturer's warranty requires a commissioning certificate, we provide that too. All documentation is issued in a single handover pack at practical completion.

This is a growing part of our work. Heat pump suitability depends heavily on the building specification, insulation levels, floor area, and heat demand. For new builds designed to post-2022 Building Regulations, we can design a heat pump system with appropriate low-temperature radiators or underfloor heating. Call us to discuss your specific project — we will give you an honest assessment of whether a heat pump is the right choice.

Yes. We carry out full heat loss calculations to BS EN 12831, size the boiler or heat pump, design the radiator or underfloor heating layout, specify controls, and produce a heating system design for Building Regulations submission. This is included for larger projects and can be quoted separately for smaller ones. A properly designed system heats correctly from day one and does not need expensive correction later.

First fix is all the work done before walls and floors are closed up — running the pipework, installing waste pipes, positioning soil stacks, and laying underfloor heating. It must be pressure-tested and inspected before the plasterboard or screed goes on. Second fix is all the final connections and fitting of visible items — the boiler, radiators, bathroom suites, taps, showers, and appliance connections. Second fix happens once the first fix is concealed and the building has dried out.

We strongly recommend it. Hertfordshire has some of the hardest water in the UK — 300–400 ppm. New heating systems, boilers, and bathroom fittings are all vulnerable to limescale from day one. Installing a whole-house water softener at the design stage is significantly easier and cheaper than retrofitting one later. It protects every appliance and fitting from the moment the water is turned on.

We install all major boiler brands including Vaillant (we are Vaillant Advance Installers), Worcester Bosch, Baxter, Ideal, and Ideal Logic. For new builds, we recommend sizing and positioning the boiler carefully at the design stage — a wrongly sized boiler is inefficient from day one. We provide a heat loss calculation to ensure the specified boiler is correctly sized for the building.

Yes — extensions are one of the most popular applications for wet underfloor heating. They typically have a concrete floor slab which is ideal for embedding UFH pipes, and the extension is usually the only part of the house being refloored, so the disruption is minimal. We design the UFH circuit at the first fix stage and install the manifold in a suitable location. See our underfloor heating page for full details.

Yes. We work with self-builders as well as professional developers and builders. Self-build projects often have a more flexible programme and require more design input from us — we are happy to be involved from the planning stage and can advise on heating system choices, specification, and Building Regulations compliance before any work starts.

Part L of the Building Regulations covers the energy efficiency of buildings. For heating systems, it requires that boilers, controls, and pipe insulation meet minimum efficiency standards. Failure to comply means the project will not pass Building Control inspection. We design all heating systems to meet current Part L requirements and issue the relevant compliance certificates on completion.

Part G covers water efficiency and hot water safety in dwellings. It requires that water-consuming fittings (toilets, taps, showers) meet maximum water consumption limits, and that hot water systems protect against scalding and Legionella. We install thermostatic blending valves, balanced hot and cold supplies, and ensure hot water is stored and distributed at correct temperatures. A Part G certificate is required for all new dwellings and significant extensions.

A magnetic filter (Magnaclean or equivalent) captures magnetite sludge from the heating water before it can circulate to the boiler heat exchanger and damage it. We fit a magnetic filter as standard on every new heating system — it is required by most boiler manufacturers to maintain the warranty, and it is a condition of Building Regulations compliance in new systems.

We agree the programme with the main contractor before starting. We attend for first fix at the correct stage, carry out pressure tests before walls are closed, and return for second fix at practical completion. We flag any issues that could affect the programme — such as specification changes, access problems, or delays to the shell — as early as possible. We carry a fully stocked van to avoid avoidable material delays.