Maximise Your Roof Space with High-Impact Loft Design – Plans from £1,395 + VAT

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If you're serious about creating a full-size new floor in your home, a mansard loft conversion is the most spacious and transformational option available. Whether you’re adding bedrooms, a home office, or an entire self-contained flat, a mansard conversion gives you the room to dream big.

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At Draw Plans, we specialise in producing detailed, fixed-price mansard loft conversion plans from just £1,395 + VAT, covering London and the Home Counties. With a fast turnaround and clear designs ready for planning and construction, we’ll help you unlock your home’s full potential.

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What Is a Mansard Loft Conversion?

A mansard conversion involves altering the structure of your existing roof to create a much steeper slope at the rear, often at a 72-degree angle, with a flat roof on top. This design maximises the internal head height and floor area, effectively creating a whole new storey.

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Mansard conversions are especially popular in:

• Terraced houses in urban areas

• Victorian and Edwardian properties

• Conservation areas, where visual harmony is essential

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A loft conversion with a mansard roof blends in well with traditional London architecture, making it an ideal choice for older homes with planning constraints.

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Benefits of a Mansard Loft Extension

• Maximum Internal Space

• Mansards provide the most additional usable square footage of any loft conversion style.

• Adds a Full New Floor

• Ideal for multiple rooms – you could add 2 bedrooms + 1 bathroom, a master suite, or even a compact apartment.

• Elegant, Symmetrical Design

• Perfect for maintaining a traditional aesthetic, especially in conservation zones.

• Significant Property Value Increase

• A high-quality mansard extension can boost resale value by 20–25%.

• Planning Permission Success

Although planning is usually required, mansard loft extensions are often favoured by planning departments in historic neighbourhoods.

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Mansard Loft Conversion Cost Guide

The cost of a mansard loft conversion reflects the structural work involved but offers excellent value in terms of space added.

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Here’s a general cost outline:

• Project TypeEstimated Build Cost (Excl. VAT)

• Mansard conversion with 1 bedroom£45,000 – £60,000

• Mansard with 2 bedrooms and 1 bathroom£60,000 – £80,000+

• Mansard with full apartment layout£75,000 – £100,000+

• Draw Plans architectural plansFrom £1,395 + VAT

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Every project is unique, and we tailor your floor plans to suit your property and goals.

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What’s Included in Our Mansard Loft Conversion Plans?

Our loft design service ensures that every technical detail is taken care of, making life easier for your builder and your council.

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Our architectural design package includes:

• Full measured property survey

• Existing and proposed floor plans, elevations, and cross sections

• Full layout for your mansard extension with detailed room design

• Staircase positioning and headroom optimisation

• Planning application drawings and submission

• PDF & CAD versions for your builder

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How to Design the Best Layout for Your Mansard Loft

Designing your mansard loft is all about space efficiency and lifestyle needs. Here are some top layout ideas:

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Floor Plan Ideas:

• Use the full-width mansard space for 2 new bedrooms and a bathroom

• Create a luxury master suite with en-suite and built-in wardrobes

• Include a study or home office nook to futureproof remote work needs

• For rental income or multi-generational living, consider a self-contained studio

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Tips for Better Integration:

• Align new stairs over your existing staircase for minimal disruption

• Position bathrooms near existing plumbing for cost efficiency

• Use matching materials and colours internally and externally

• Install fire-rated doors and insulation to comply with Building Control

• Consider lighting zones and rooflights for natural light

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Planning Permission for Mansard Conversions

Unlike simpler loft conversions, a mansard loft extension almost always requires planning permission due to the changes to the roofline.

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Draw Plans will:

• Advise on your likelihood of approval

• Prepare and submit all planning drawings

• Liaise with your local planning authority

• Respond to any feedback or required changes

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We have extensive experience securing approvals in even the strictest boroughs, including within conservation areas across London.

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Where We Work

We create professional mansard loft conversion plans across:

• London (all boroughs)

• Surrey

• Essex

• Kent

• Hertfordshire

• Buckinghamshire

• Berkshire

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Wherever you’re based in the Home Counties, we can help.

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Testimonials

“Draw Plans helped us design a stunning mansard extension with two bedrooms and a bathroom. Their planning knowledge was spot-on — we were approved with no hassle.”
— Rachel M., Clapham

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“We thought a loft conversion wasn't possible in our conservation area, but Draw Plans made it happen. The mansard design fits beautifully with our Victorian home.”
— David B., Richmond

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“Clear plans, great advice, fast turnaround. Our builder had no issues working from Draw Plans' drawings, and Building Control approved them right away.”
— Tom and Elaine W., Camden

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Why Choose Draw Plans?

• Fixed price from £1,395 + VAT

• Specialists in loft conversion design

• In-depth planning and building regs experience

• Serving London and surrounding counties

• Quick turnaround with clear communication

• Trusted by homeowners, builders, and developers

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Ready to Start Your Mansard Loft Conversion?

A mansard loft conversion is one of the smartest investments you can make in your home — and Draw Plans makes it simple.

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Let us provide you with expertly drawn, builder-ready plans for your loft project from just £1,395 + VAT.

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Contact us now for a free quote and advice on your next step. We’ll help you maximise your loft space with professional plans you can trust.