Residential extension

Polypipe provides complete product range for residential extension

Proving just why it deserves the name Polypipe Building Products, the company has provided end to end systems for a typical extension project from groundworks through to plumbing and everything in between.

Situated in Doncaster, this unassuming three bed semi-detached house was built to match the rest of the estate. But, having lived there for seven years, the owners decided to take the plunge and make the most of their oddly shaped corner plot, to turn their cut and paste house in to something more unique.

First on their wishlist was enlarging the box room to give the house three good sized double bedrooms. This meant creating a double height extension to the side of the property, which also gave the owners the opportunity to add a utility room and downstairs bathroom to their footprint. Second on the wishlist was a large multi-purpose open living space. By adding a single height rear extension, the homeowners got their wish and created a large kitchen/diner/snug, finished by 6m wide bifold doors with a view on to the garden. This single height space has a dramatic vaulted ceiling with skylights, flooding the new space with natural light.



Residential Extension


  • Plot Drainage
  • TDI Insulation
  • Rainwater
  • Underfloor Heating
  • Soil & Waste
  • Plastic Plumbing

Everything you need for a residential extension

Polypipe was able to offer products for every stage of the build, beginning with plot drainage and ending
with plastic plumbing.

Plot Drainage

At the start of the project, the drains were re-sited to accommodate the new footprint. The builders relocated two inspection chambers and accompanying pipework. The builders also needed to plan in the drainage from the kitchen sink which would be positioned in a new island unit in the centre of the new space.

TDI Insulation

The second stage was to insulate the cavities created by the new doors and windows. For this, Polypipe’s WCMulticor from the TDI range was used. The product comprises of a wedge of insulation with groves to indicate different widths, slotted in to a plastic casing. The builders simply cut the product to the required cavity width on site and then used the plastic casing to tack the product in to place before the new doors and windows were fitted.


The addition of new rooflines necessitated additional guttering, downpipes and associated fittings. The homeowners chose black sovereign gutter profiles and square downpipe. Polypipe was able to offer a lightweight, easy to install product that matched the aesthetic of the rest of the street.

Underfloor Heating

Whilst undertaking extensive renovation works that necessitated a new boiler, the owners decided to overhaul their home heating, installing underfloor heating throughout the ground floor. Polypipe’s Overlay system was chosen so that the new floor could be built up to the height of the existing floor and the system could be fitted in one go. The homeowners chose Polypipe’s new auto-balancing manifold and Smart Plus controls.

The homeowners also took advantage of Polypipe’s Smart Plus controls system to pair their upstairs radiators to their downstairs UFH system, and control their whole home heating via Polypipe’s mobile app. This means the whole house can be set to a programme or rooms can be controlled individually to suit whoever is using a given space.
Taken together, Polypipe’s holistic solution has significantly improved the home’s heating system, reducing the homeowners’ heating bills and their environmental impact. It has also allowed them to redecorate as they wished, without working around bulky radiators, and create bespoke comfort zones throughout the different areas of the home.

Unique to Polypipe, the auto-balancing manifold features a valve which prevents over supply of hot water to any one circuit and optimises the hot water needs of the system as a whole. This eliminates any wasted energy heating more water than is needed, and therefore improves the system’s overall environmental efficiency.

This product also offers benefits the heating engineer who no longer needs to spend an unpredictable amount of time balancing the underfloor heating system themselves by gaging the amount of water flow needed for each underfloor heating zone, before readjusting the flow meters manually. The flow rate can simply be selected, set, and left to balance itself, making the system easier to install, and more efficient for the end user.

Soil & Waste

As the homeowner had added a new utility, downstairs toilet, sink and shower; as well as repositioning the kitchen sink, a new soil stack and a large amount of waste pipe and fittings were required.
Polypipe was able to provide a low-level trap to fit beneath the shower tray, alongside a bottle trap for beneath the w/c sink and a combined sink and appliance trap to service the kitchen sink and washing machine.

The homeowners benefited from the newest improvements to Polypipe’s waste range, the entirety of which is protected by market-leading BioCote technology.

This scientifically proven antimicrobial technology is exclusive to Polypipe and will provide lasting and effective protection against harmful bacteria, mould, fungi and viruses, eliminating up to 99.99% of them within the waste system. This significantly minimises the build-up of bio-film, reducing unpleasant odours and blockages.

The bottle trap used was the WP46 which is Polypipe’s Help for Heroes endorsed product, meaning Polypipe donates 79p to the charity with every trap purchased. It features a host of installation improvements, including the Fit-Rite insertion aide and new finned seal. It’s the only traps range on the market with a Kitemark and is part of the BioCote protected waste range.

Plastic Plumbing

Finally Polypipe’s PolyMax range was used for the extension’s hot and cold water requirements. PolyMax is a white push fit plumbing fitting, typically used in surface mounted installations where the plumbing may sometimes be on show.

PolyMax is an extremely secure range of plumbing fittings. Once installed, they cannot be removed without our handy release tool, meaning no one’s going to mess with them.

An ideal choice for surface-mounted installations, PolyMax is easy to use, easy to install and easy to get excited about.

  • Suitable for most hot and cold water supply and heating applications
  • Sleek, attractive white design is perfect for exposed use
  • Leak-proof – giving you complete peace of mind
  • Compatible with our sealed stiffener for added security


Slim, sleek and attractive, PolyMax is compatible with polybutylene or copper pipe systems and can be easily demounted using our handy release tool. Because it requires a tool for removal, it provides an extremely secure joint for a leak-proof system giving the plumber and the homeowner complete peace of mind.

Making the difference

The homeowner said, ‘Despite its fairly modest scale, it’s hard to overstate the difference this extension has made to the way we live in our house. I keep changing my mind about my favourite part.

It has provided simple, practical, pleasures like not having to traipse through the muddy garden to the freestanding garage on a winter’s evening to get to the freezer or clothes dryer because there just wasn’t enough space for them indoors. And our new side door straight in to the utility and downstairs shower means I no longer have to drag a muddy dog through a clean house to wash him down after walks!

But it is truly wonderful to come home to a warm house, settle down in the new snug and admire the view on to our garden.’


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