Double Storey Extension Builders in Manchester

A double-storey extension is a whole-house project

A double-storey extension can add a ground-floor room and bedroom space above without spreading the build across as much garden as a large single-storey design. That makes it an option for homeowners who need extra space on more than one level. It also makes the structural decisions more significant. Foundations, walls, roof connections, upper-floor layout, openings and the relationship with the existing house must be resolved together.

MNB Brickwork provides the brickwork and external structural-build elements for double-storey extensions across Greater Manchester. A survey is used to understand the property, access, existing walls, levels and the approved or emerging design. The work then follows the relevant drawings and structural information, with clear handover points for the architect, engineer, building-control body and specialist trades.

Start with the layout, then test the build

A useful double-storey layout starts by deciding what changes on each floor. Downstairs, that may be a kitchen, dining space or family room. Upstairs, it may be an additional bedroom, bathroom or a reworked landing. The stair position, the opening to the existing rooms, natural light, roof form and external proportions all need consideration before the wall lines are fixed.

The build then tests that layout against the property. A new foundation cannot be selected from a sketch alone. The existing drainage, the proposed structure, delivery access, party-wall considerations and the position of neighbours' windows can affect what is practical. MNB's role is to assess the construction elements and work from the information prepared for the individual home.

Planning permission and permitted development

A double-storey rear extension can sometimes be permitted development, but only when it meets every relevant condition. It must project no more than 3 metres beyond the original rear wall and be at least 7 metres from the boundary opposite that wall. The roof pitch should match the existing house as far as practicable, and upper-floor side windows have additional privacy conditions. These are not standalone permissions.

A two-storey side extension needs householder planning permission. More-than-one-storey rear extensions are also restricted on designated land. Previous extensions, local planning conditions, Article 4 directions and the exact boundary arrangement all matter. Check the proposed design with the council or seek a lawful development certificate before making decisions based on a general online rule.

Double-storey extension cost

The cost of a double-storey extension cannot be set responsibly from an online description. Although some external costs are shared across two floors, the project also involves an upper floor, roof work, a larger structural connection to the existing house, more detailed design and a greater coordination requirement. The size and specification are only part of the picture.

As a broad UK guide only, <a href="https://www.checkatrade.com/blog/cost-guides/house-extension-cost/" target="_blank" rel="noreferrer" style="color:#e05c3a;text-decoration:underline;">Checkatrade's June 2026 cost guide</a> lists £108,000 to £180,000 before VAT for a typical 60m² two-storey extension. This is not an MNB price or a Greater Manchester price promise. Every job is quoted after a free survey, and MNB will confirm the scope before issuing a project-specific quotation.

Building Regulations and construction stages

Planning permission and Building Regulations are separate. Building control deals with the technical work, including the construction of the extension, insulation, structure, drainage, fire-safety considerations and the details of the connection to the home. The appropriate route should be agreed with a building-control body before site work is programmed.

During construction, foundations, substructure, floor, cavity walls, structural openings, roof work, windows and doors need to be sequenced around the approved information. Inspections happen at the relevant stages. A good programme allows for the information, notices, materials and weather that affect each stage. It should not promise a completion date before those conditions are known.

Brick matching and the external shell

A second storey makes the old-to-new junction particularly visible. Brick size, tone, texture, mortar joints, the roofline and the alignment of openings need to make sense with the original elevation. A close match is not always available, especially on weathered brickwork, but samples and careful setting-out can avoid a new wall that feels unrelated to the house.

MNB assesses the existing masonry in daylight and discusses the practical options before materials are ordered. The same attention goes into cills, lintels, eaves, rainwater goods and the transition to existing walls. Those details form part of the structural-build conversation, not an afterthought once construction has begun.

Double-storey extensions across Greater Manchester

MNB Brickwork covers double-storey extension structural-build work in Worsley, Salford, Bolton, Wigan, Stockport and Manchester. The location pages can help homeowners find their area, but each project needs a property-specific review. A conservation area, an Article 4 direction, an earlier extension or a particular boundary can change the planning and design route.

Before the survey, it is useful to gather any estate-agent plans, old permissions, photographs of the rear and side of the house, and early layout ideas. None of these have to be polished drawings. They simply help the first conversation focus on the existing property, the new space you need and the information required to take the design forward.

Bring your drawings or early ideas to a free survey. MNB can discuss the foundations, masonry, structural openings and external shell, then identify the information needed before a written quotation is prepared. Call 07821 482488 or contact MNB Brickwork to arrange a visit.

What the structural-build scope considers

Structural-build scope based on the approved design, site survey and relevant engineering information

Foundations, cavity walls, openings and external shell work coordinated in sequence

Existing masonry and roofline considered before the brickwork is set out

Clear working relationship with architects, structural engineers and building control

Free Greater Manchester surveys before a project-specific quotation is prepared

No fixed online pricing or programme promises before the property has been assessed

Questions homeowners ask

Does a double-storey extension need planning permission? Many double-storey extensions need householder planning permission. A rear extension of more than one storey may be permitted development only when every limit and condition is met. A two-storey side extension needs planning permission. Confirm the exact proposal with the council.

What is the 3-metre rule for a double-storey rear extension? Under the householder permitted development rules, a more-than-one-storey rear extension must not project more than 3 metres beyond the original rear wall and must be at least 7 metres from the boundary opposite that wall, subject to other restrictions.

Can I build a two-storey side extension under permitted development? No. A side extension of more than one storey needs householder planning permission. The design, impact on neighbours and any local policy considerations should be checked before work is programmed.

How much does a double-storey extension cost? There is no dependable fixed online price for a double-storey extension. The final scope depends on the survey, foundations, structural design, access, roof work, services, approvals and finish. MNB Brickwork quotes every job after a free survey.

Do I need Building Regulations approval as well as planning permission? Usually, yes. Planning and Building Regulations are separate checks. Building control considers technical matters such as structure, fire safety, insulation, drainage and the details of the work.

Can MNB Brickwork work with my architect and structural engineer? Yes. MNB Brickwork can work from the approved drawings and structural information, coordinating the brickwork and external structural-build elements with the relevant professionals and trades.