Design and build two-storey extensions in County Londonderry

County Londonderry at a glance

Nation: Northern Ireland
Price region: Northern Ireland
Postcode areas: BT
Towns covered: 11 listed below, plus surrounding villages
Site visits: Free, no obligation

What a design and build project involves

This service suits you if you want one team accountable from the first visit to the completion certificate. We manage the design, approvals and build, and the work is carried out by vetted teams working under S&K. Because the same team designs and builds, costs are checked as the design develops. Every project starts with a free site visit.

County Londonderry towns we list: Derry (BT48), Coleraine (BT51), Limavady (BT49), Magherafelt (BT45), Portstewart (BT55) and Portrush (BT56). Every other address in County Londonderry is covered as well.

Fees

The design stage is priced in writing before it starts, and the build is a fixed price in writing once the design is agreed.

Rules in Northern Ireland

In Northern Ireland, design and build covers the permitted development check or a planning application (£347), building control approval from the council under the Technical Booklets and neighbour matters under common law and title deeds, as there is no Party Wall Act. Planning decisions often take longer, which we build into the programme.

Approval in Northern Ireland: Planning application for works to a house: £347. Councils aim to decide local applications within an average of 15 weeks; many take longer.

Building control: Building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets.

There is no Party Wall Act in Northern Ireland. Shared walls and boundaries are a matter of title and common law, so we agree access and record conditions with neighbours before work starts.

Getting the design right

Cost checking as you design

Because the people drawing the extension also build it, each design option comes with a guide cost. That avoids the common problem of an approved design that turns out to be too expensive once builders price it.

How the stages work

We start with a free site visit, then a design stage priced in writing before it begins. That covers the survey, design, approvals, structural design and building regulations. Once the design is agreed, the build price is fixed in writing before work starts.

How we work in County Londonderry

Start at your house
We come to your home in County Londonderry, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Northern Ireland before drawing in detail.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Towns we cover in County Londonderry

Design and build two-storey extensions in County Londonderry: questions

What is the difference between design and build and using an architect?

With an architect, you appoint them for the design and approvals, then find and manage a builder separately. With design and build, one team does both, so cost, buildability and approvals are considered together and there is one point of contact. Some people still prefer to hire an architect separately.

When is the build price fixed?

Once the design is agreed and the drawings, structural calculations and specification are complete. Before that we give guide costs at each stage. The fixed price is set out in writing before work starts, and any changes you ask for after that are priced separately before they are made.

Who builds my extension?

Your extension is built by vetted teams working under S&K, with the project managed by us from design to completion. You have one point of contact throughout, and the same team that prepared the design is responsible for the build.

Neighbouring areas

All extension services in County Londonderry · About design and build two-storey extensions