Building & Construction Services in London

Small enough to listen, big enough to deliver. Explore our core services below and start your project today.

New Build

Residential and commercial developments delivered on time and within budget, from design coordination to handover.

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Refurbishments

Full property upgrades: structural changes, kitchens, bathrooms, flooring, decoration and compliance.

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Property Maintenance

Reactive and planned works for homes and businesses: electrical, plumbing, carpentry, painting and more.

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Retrofitting

Energy-smart upgrades: insulation, windows, heating & controls, helping reduce bills and carbon footprint.

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Popular Project Types

House Extensions

Rear, side return and wrap-around extensions with full structural works, MEP and finishes.

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Loft Conversions

Maximise unused space with dormers, hip-to-gable, L-shape, skylight (Velux) and more.

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Basement Conversions

Specialist excavation, structural works and waterproofing (Type A/B/C) with full fit-out.

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Loft Conversion Types

Choose the configuration that fits your home and goals.

Dormer Loft

Add a full-height room with excellent headroom and natural light.

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Hip-to-Gable

Extend the roofline to unlock full-width usable space.

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Mansion Block

Heritage-sensitive lofts for mansion blocks & period buildings.

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L-Shape Dormer

Ideal for terraces—two rooms plus bathroom layout.

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Pod Dormer

Create an extra bedroom or en-suite at the rear pod.

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Skylight / Velux

Fast, cost-effective conversion with roof windows only.

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Roof Terrace

Design, structure, drainage and finishes for roof decks.

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House Extension Types

Choose the extension style that best suits your property and lifestyle.

Rear House Extension

Extend into the garden to create spacious kitchens, living rooms, or open-plan layouts.

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Side Return Extension

Use the alleyway space to widen kitchens and dining areas in terraced or semi-detached homes.

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Wrap Around Extension

Combine rear and side return for maximum space—ideal for large open-plan family areas.

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Double Storey Extension

Add bedrooms, bathrooms or office space with a two-floor extension that boosts value.

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The Bigness Process

How we deliver projects on time, on budget, with minimum disruption.

Planning & Preparation

  • Clear scope & objectives to avoid scope creep.
  • Realistic plan with SMART milestones.
  • Accurate takeoffs & surveys to prevent surprises.
  • Risk & contingency buffers for time and budget.

Execution & Management

  • Right team with multi-skilled capabilities.
  • Clear communication with clients & vendors.
  • Progress monitoring (incl. earned value).
  • Technology-driven project management.

Minimising Disruption

  • Value engineering for compliant, cost-effective solutions.
  • Proactive risk management & supplier partnerships.
  • Flexible & adaptable approach to keep work moving.

Frequently Asked Questions

Answers to the most common questions about our construction and property services in London.

Q Do I need an architect, or can Bigness handle design?
We’re happy to collaborate with your architect or deliver a full **design & build** service. For lofts, extensions and refurbishments we can manage drawings, structural design and building control submissions.
Q Do you manage planning permission and building control?
Yes. We advise whether your project falls under **Permitted Development** or requires planning consent, prepare the application, handle **party wall** matters where needed, and coordinate **Building Control** sign-off.
Q What areas do you cover?
We cover **all London boroughs** and the surrounding areas (Greater London, parts of Surrey, Essex and Kent).
Q How long do projects typically take?
Timelines vary by scope. Typical ranges:
• Loft conversion: **6–10 weeks** · House extension: **10–16+ weeks** · Refurbishment: **4–12+ weeks**
We create a detailed programme with milestones before starting on site.
Q Can we live in the property during works?
Often, yes—especially for lofts and some refurbishments. We set up dust protection, safe access and phased works. For major structural or basement projects, temporary accommodation may be more practical.
Q Are you insured and qualified?
Yes. Bigness carries full public & employer’s liability insurance. Trade specialists are appropriately qualified (e.g. Gas Safe for heating, certified electricians for compliance), and projects follow strict **Health & Safety** procedures.
Q Do you offer fixed-price quotes? What’s included?
We provide clear, itemised **fixed-price quotations** based on drawings and a detailed scope. Inclusions and exclusions are stated up front, along with a realistic programme and payment schedule.
Q What warranties do you provide?
Workmanship warranty is provided on completion, plus manufacturer warranties on installed products and systems. You’ll also receive certificates and manuals where applicable.
Q Can you help with energy-efficient upgrades and retrofitting?
Absolutely. We deliver **insulation upgrades, efficient heating/controls, windows & doors** and other retrofit measures to improve comfort and reduce running costs.
Q How do we get started?
Tell us about your project and we’ll arrange a site visit or video call. You’ll receive a clear proposal with scope, costs and timeline. Request a Free Quote →

Not sure where to start?

Tell us about your project and we’ll advise the best route.