Design & Build Extensions in Swindon
Thinking about extending your home but don't have architectural plans yet? Craig Donnelly Building Contractors Ltd offers a comprehensive design-and-build extension service throughout Swindon and the surrounding Wiltshire area.
Whether you're considering a larger kitchen, an open-plan family living space, an additional bedroom or a double-storey extension, we can help you take your project from the initial ideas through to construction.
Our design-and-build service brings together experienced local builders, architectural design and professional building project management, helping homeowners plan their extensions with confidence.
As an award-winning building company, we pride ourselves on quality workmanship, clear communication and a straightforward approach to home extensions.
Award-Winning Design & Build Extension Specialists in Swindon
Planning a house extension can feel complicated, particularly if you're unsure where to begin.
At Craig Donnelly Building Contractors Ltd, we provide a structured process that allows homeowners to explore their ideas, understand the estimated construction costs and arrange architectural drawings before progressing to a detailed building quotation.
We were proud to receive a 2022 LABC Building Excellence South West Regional Award, recognising the quality of our building work.
Our aim is to make the extension process as straightforward as possible, providing clear guidance and professional construction services from the early planning stages through to completion.
Our Design & Build Extension Process
Every home extension starts with an idea. Our step-by-step process helps customers understand the work involved, the likely building costs and the necessary approvals before construction begins.
Step 1 — Initial Consultation and Property Visit
When you contact us about a proposed extension, we arrange a visit to your property to discuss your ideas and requirements.
During the visit, we look at the existing property, discuss the type of extension you're considering and take relevant measurements.
This gives us an understanding of your proposed project and allows us to prepare an initial building estimate.
Step 2 — Initial Building Estimate
Following our visit, we provide an initial estimate for the proposed extension based on the information available.
This helps you understand the likely construction costs before committing to architectural drawings.
The estimate is an early indication of costs rather than a final fixed quotation. The final price will depend on the detailed architectural plans, structural requirements and agreed building specifications.
Step 3 — Architectural Drawings and Design
If you're happy with the initial estimate and would like to proceed, we can arrange for our architect to visit your property and prepare architectural drawings.
The architect will work with the proposed design and relevant requirements to develop plans for your extension.
Architectural fees are payable directly to the architect by the customer.
Once the first draft drawings have been prepared, they are provided to us so we can review the proposed construction in greater detail.
Step 4 — Fully Detailed Building Quotation
Using the architectural drawings, we prepare a fully detailed quotation for the proposed extension.
This sets out the agreed construction work, specifications and associated building costs.
Where structural engineering information is required, we can help arrange the necessary professional input. Structural engineering fees and other agreed third-party costs are charged separately.
Our detailed quotation provides a clearer understanding of the proposed building work before you decide whether to proceed.
Step 5 — Building Contract Agreement
Once you're happy with the detailed quotation and wish to proceed, we prepare and sign a written building contract.
The building contract is signed before the planning application is submitted and is conditional upon obtaining the necessary planning approval.
The contract sets out the agreed building works, quotation, payment arrangements and relevant terms and conditions.
This ensures both parties understand the proposed project and the conditions that must be satisfied before construction can begin.
Step 6 — Planning Applications and Building Regulations
Following the contract agreement, our architect coordinates the appropriate planning applications and associated drawings.
Depending on the proposed extension, this may involve a planning permission application, a lawful development certificate or other relevant approval procedures.
We can also help coordinate the Building Control process and any required structural engineering information.
Planning application charges, Building Regulations fees and independent professional fees are payable separately by the customer.
Planning approval is not guaranteed and remains subject to the relevant authority's decision.
Step 7 — Planning Approval, Booking Deposit and Construction
Once the necessary planning approval has been granted, the booking deposit becomes payable in accordance with the agreed building contract.
The remaining pre-construction requirements, including relevant Building Regulations arrangements, must also be addressed before work begins.
We can then agree the construction programme and coordinate the building work.
From groundworks and foundations through to brickwork, roofing, structural alterations and internal plastering, our team manages the agreed construction stages to deliver your new extension.
Planning Approval, Contracts & Booking Deposits
We believe homeowners should understand the financial commitments involved in a design-and-build extension before proceeding.
Our process separates architectural and planning costs from the building booking deposit, providing clarity about when different payments become due.
What Happens If Planning Permission Is Refused?
If the initial planning application is refused, we will work with our architect to explore suitable amendments to the design where possible.
Revised architectural drawings and a further planning application may be required, depending on the reasons for refusal.
Additional architectural, planning or professional fees may apply.
If planning permission ultimately cannot be obtained and the project cannot proceed, the building contract will come to an end in accordance with its agreed conditions.
No building booking deposit is payable if the necessary planning approval cannot be obtained.
When Is the Booking Deposit Payable?
The building booking deposit becomes payable only after the necessary planning approval has been granted, as specified in the written building contract.
No building booking deposit is required simply because the customer has agreed to the initial estimate, commissioned architectural drawings or signed the conditional building contract.
Architectural and Planning Fees
Architectural drawing fees are payable directly to the architect.
Planning application charges, Building Regulations fees, structural engineering fees and other agreed third-party professional costs are payable separately by the customer.
These costs may still be incurred if planning permission is refused or the proposed extension cannot proceed.
The full contractual terms, payment arrangements and any applicable cancellation rights will be provided in the written agreement.
Types of House Extensions We Can Design & Build
Our design-and-build service can help homeowners plan a range of residential extension projects, subject to the property, proposed design and necessary approvals.
Single-Storey Extensions
Single-storey extensions can create additional ground-floor living space, including larger kitchens, dining areas and family rooms.
They can incorporate features such as rooflights, vaulted ceilings and large glazed doors, depending on the architectural design.
Rear House Extensions
Rear extensions are a popular way to increase living space while creating a better connection between the home and garden.
They are particularly suitable for open-plan kitchen and dining areas, subject to the available space and relevant approvals.
Double-Storey Extensions
Double-storey extensions can provide additional accommodation across two floors.
They may create space for larger ground-floor living areas alongside additional bedrooms, bathrooms or other first-floor accommodation.
Kitchen and Open-Plan Living Extensions
Many homeowners choose to extend their properties to create larger, more practical kitchens and open-plan family living spaces.
Where required, we can coordinate structural engineering input and the installation of steel beams to create suitable openings between the existing home and the new extension.
Our Complete Extension Building Service
Once the architectural plans, contract and necessary approvals are in place, we can coordinate the construction of your extension from the initial groundworks through to the agreed finishing stages.
Our building services can include:
Groundworks, Foundations and Drainage
Excavation, concrete foundations, drainage alterations and associated groundwork construction in accordance with the approved drawings and relevant requirements.
Brickwork and Structural Construction
Construction of cavity walls, blockwork, brickwork and structural elements, using materials specified for the project and matching the existing property where practical.
Roofing and Roof Structures
Construction of pitched roofs, flat roofs and vaulted roof structures, depending on the architectural design and agreed specifications.
Structural Steelwork and Internal Alterations
Installation of structural steel beams and associated building alterations where required by the structural engineer's design.
Plastering and Internal Building Work
Insulation, plasterboarding, plastering and associated internal construction work to prepare the new extension for its final finishes.
Plumbing and electrical works can also be coordinated where included within the agreed building specification.
Painting and decorating, flooring and tiling are excluded from our standard building quotations, although we can recommend trusted tradespeople for these services.
Landscaping and external garden reinstatement are also excluded as standard unless separately agreed.
Why Choose Craig Donnelly Building Contractors Ltd?
Choosing the right building contractor is an important part of planning a successful home extension.
Our design-and-build service offers homeowners a practical route from their initial ideas through to construction, with clear information at each stage.
We offer:
- Award-winning workmanship — recognised at the 2022 LABC Building Excellence South West Regional Awards.
- Experienced local builders — undertaking house extensions throughout Swindon and the surrounding Wiltshire area.
- Initial property consultations — discussing your ideas and taking measurements before preparing an estimate.
- Architectural design coordination — arranging an architect to prepare drawings and coordinate relevant applications.
- Detailed building quotations — prepared once the first architectural drawings are available.
- Clear written contracts — setting out the agreed building work, payment arrangements and planning conditions.
- Comprehensive insurance — providing additional peace of mind.
- Professional building project management — coordinating construction from foundations through to completion.
- Free, no-obligation initial estimates — helping homeowners understand likely building costs before commissioning plans.
Design & Build Extension Quotations in Swindon
If you're thinking about extending your home but don't yet have architectural plans, we'd be happy to discuss your ideas.
Whether you're considering a single-storey extension, a rear kitchen extension or a larger two-storey project, Craig Donnelly Building Contractors Ltd can help you understand the likely construction costs and the next steps involved.
We can arrange an initial property visit, discuss your requirements and provide a free, no-obligation building estimate.
Email info@craigdonnelly.co.uk to discuss your proposed house extension and arrange an initial consultation.
Craig Donnelly Building Contractors Ltd — Quality You Can Trust, Award-Winning Builders.