House Extensions London
House extension construction across London including rear extensions, side-return extensions, wraparound extensions and larger residential alterations. Crestane can coordinate groundwork, foundations, structural steel, roofing, glazing, building services, kitchens, interiors and refurbishment as part of one project.
Request an Extension Quote Explore Extension TypesPlanning to extend your home in London?
Tell us about your property, the type of extension you are considering and any drawings or information already available. Crestane can review the extension as a complete construction project rather than only one individual trade package.
One contractor from structure to finish
A house extension can require groundworks, structural construction, roofing, glazing, electrical and plumbing works, kitchens, plastering, flooring and decorating to work together.
Request an extension quote
Provide the main project details below.
Create more space without treating every trade as a separate job
A house extension can transform the way an existing property works. It can create a larger kitchen and living area, provide additional bedrooms, improve circulation or allow the entire ground floor arrangement to be reconsidered.
Crestane Construction provides house extension construction across London for clients requiring individual building packages or a coordinated extension and refurbishment project.
Extension work can involve excavation, foundations, drainage, structural walls, steel beams, new roof construction, windows, doors, electrical installations, plumbing, heating, plastering, kitchens, flooring, carpentry and decorating.
Where the existing house is also being refurbished, the new extension can be integrated with those works so the original property and new construction are considered together.
Different ways to extend a London home
The appropriate extension depends on the existing house, available space, proposed layout and any relevant design or approval requirements.
Rear Extensions
Extend into the rear of the property to create additional internal floor area, often used for larger kitchens, dining rooms and open-plan living spaces.
Side-Return Extensions
Make use of side-return space commonly found alongside terraced and period London houses to widen the existing ground floor.
Wraparound Extensions
Combine rear and side extension space to create a larger reconfigured ground-floor footprint.
Double-Storey Extensions
Create additional space across more than one floor where the property, design and relevant approvals allow.
Kitchen Extensions
Extend and reconfigure the ground floor around a larger kitchen, dining and living arrangement.
Extension & Refurbishment
Combine new floor space with refurbishment of the existing property so the completed home works as one coherent scheme.
What can be included in an extension project?
Extension construction involves much more than building the external walls. Each stage needs to connect correctly with the existing property and the final internal layout.
Preparation of the work area and practical access for the proposed extension construction.
Excavation, formation, below-ground work and associated preparation.
Construction of the required foundations based on the design and project requirements.
Alterations or new drainage where the extension affects existing arrangements or introduces new requirements.
Construction of the new extension structure and associated connection to the existing building.
Beams and steelwork where required to create openings or support the proposed structure.
Flat or pitched roof construction depending on the extension design.
External glazing, doors and openings incorporated into the extension envelope.
Services coordinated with the new layout, kitchen and other spaces.
Internal wall and ceiling preparation following the main construction and services work.
Kitchen construction and installation can form part of the extension where required.
Final finishes that connect the extension with the existing home.
The new extension must connect properly with the existing house
Many extension projects involve removing or altering part of the original rear or side wall so that the existing property can connect into the new space.
Where structural elements are affected, suitable structural design information should establish how loads are supported and transferred through the altered building.
This can include steel beams, columns, padstones, foundations, roof structures and other structural components depending on the design.
Coordinating the structural work with the wider extension prevents the structure from being treated separately from the kitchen, services, ceilings and finishes that depend on it.
Extending the house is often only part of the project
A new extension often affects much more than the area being added. Opening the rear of a property may change the entire ground-floor layout, kitchen position, electrical arrangement, plumbing, flooring and finishes.
For this reason, many extension projects are better considered alongside refurbishment of the existing house.
Crestane can coordinate extension work with wider property refurbishment so that old and new areas are completed as part of one overall construction programme.
This may include structural alterations within the existing house, a new kitchen, bathrooms, rewiring, plumbing, plastering, flooring, carpentry and complete decoration.
If your project includes extensive existing-house renovation, you can also view our House Refurbishment London service.
Establish the project requirements before construction begins
The approvals required for a house extension depend on the property, location, design and scope of the proposed work.
Some extension projects may fall within permitted development rights, while others may require planning permission. Building Regulations requirements are separate and should also be established for the specific project.
Structural alterations normally require appropriate design information where load-bearing parts of the existing property or proposed extension are affected.
Other project considerations can include drainage, boundary conditions, neighbouring property, access and any restrictions applying to the building or location.
Identifying these matters before construction helps establish a clearer build scope and reduces the risk of major changes being introduced after work has started.
What affects the cost of a house extension?
The cost of extending a house depends on much more than floor area. Structure, access, specification and the amount of work required to the existing property can significantly affect the overall project.
From existing house to completed extension
Project Review
Understand the property, proposed extension, drawings and overall client requirements.
Scope
Establish the construction, structural, services and finishing packages required.
Groundworks
Progress excavation, foundations, drainage and below-ground construction.
Structure
Construct walls, steelwork, openings, roof and the main building envelope.
Services & Interior
Coordinate electrical, plumbing, plastering, kitchen and internal construction.
Finish & Complete
Flooring, carpentry, decoration, final installations and completion of the agreed scope.
Extensions for different types of London homes
London housing varies considerably in layout and construction. The extension needs to respond to the existing property and available space.
What should you send with an extension enquiry?
You can contact Crestane before every project detail is finalised. The following information helps us understand what you are trying to build.
Property Address
Provide the postcode and basic information about the existing house.
Extension Type
Tell us whether you are considering a rear, side, wraparound or other extension.
Drawings
Architectural and structural drawings are useful where already available.
Photographs
Existing property and garden photographs help communicate the current arrangement.
Wider Works
Tell us if the project also includes a kitchen, refurbishment or structural alterations.
Timescale
Provide your intended start period even if the exact date is not yet fixed.
An extension can connect with wider construction works
House extension projects across Greater London
Crestane considers suitable house extension and residential construction projects throughout Greater London.
Frequently asked questions
What types of house extensions does Crestane undertake?
Suitable projects can include rear extensions, side-return extensions, wraparound extensions, double-storey extensions, kitchen extensions and extensions forming part of a wider refurbishment project.
Can Crestane build the whole extension?
Yes. The scope can include groundworks, foundations, structural construction, roofing, glazing, electrical and plumbing work, plastering, kitchens, flooring, carpentry and final finishes.
Can you build an extension and refurbish the existing house?
Yes. Extension construction can be coordinated with refurbishment of the existing property where the client is undertaking a broader renovation.
Can you remove the existing rear wall to create an open-plan space?
Structural alterations and openings can form part of the extension project where supported by the appropriate structural design.
Can structural steel be included?
Yes. Structural beams and associated construction can be included where required by the proposed design.
Can the new kitchen be included in the extension project?
Yes. Kitchen installation can be coordinated with plumbing, electrical work, plastering, flooring, tiling and the wider extension construction.
Do house extensions need planning permission?
Requirements depend on the property, location and proposed design. Some projects may be possible under permitted development rights, while others may require planning permission. The position should be established for the specific property and scheme.
Are Building Regulations separate from planning permission?
Yes. Planning and Building Regulations are separate matters. The relevant requirements should be established for the specific extension before construction progresses.
How much does a house extension cost in London?
The cost depends on size, type of extension, foundations, structural requirements, glazing, roof design, building services, kitchen specification, finishes, access and the amount of refurbishment required to the existing house.
Can you undertake side-return extensions in London?
Yes. Suitable side-return extension projects can be considered, including extensions forming part of a larger ground-floor reconfiguration.
Can you undertake wraparound extensions?
Yes. Wraparound extensions combining rear and side space can be considered where appropriate for the property and proposed design.
Do I need drawings before contacting Crestane?
No. You can make an initial enquiry before drawings are complete. If architectural or structural drawings already exist, send them because they can help clarify the intended construction scope.
Which parts of London does Crestane cover?
Suitable house extension projects can be considered throughout Greater London including Central, North, North West, West, South West, South, South East and East London.