Why would I use SpaceUp?

Space Up offers a comprehensive service from initial design through to construction completion. We handle all aspects of your project, ensuring a seamless experience with a single point of contact throughout.

One of our consultants will contact you shortly to discuss your project in more detail. We'll arrange a convenient time for an initial consultation, either virtually or in person, to better understand your requirements and provide more tailored advice.

How do we design your space?

Our design process begins with understanding your needs, lifestyle, and aspirations. We then create concept designs and detailed plans that maximize space, light, and functionality while adhering to planning regulations and building codes.

How will I manage my project?

You'll have a dedicated point of contact throughout the project. We manage every stage — from planning and coordination to the final finishes — while keeping you informed with clear communication and regular updates every step of the way.

Do you guarantee planning permission?

While we can't guarantee planning permission, our experienced team has an excellent track record of successful applications. We work closely with local planning authorities, understand their requirements, and design with planning constraints in mind to maximize the chances of approval.

Open-plan kitchen and dining space with an island and glazed doors to the garden

Home
Cost Guide

Project Pricing

Cost guide for
Extensions
Loft conversions
Home renovations

Get a clearer understanding of typical project costs, what influences pricing, and how we approach budgeting for high-quality home improvements across London.

Loft Conversions

Velux Loft Conversion

Velux loft conversion includes installing Velux windows in the loft space without making any structural changes. This allows the natural light to flood in and make the space bright and fresh, perfect for a modest bedroom, reading nook or even a home office.

Estimated Cost

Starting from £35K

Dormer Loft Conversion

A Dormer loft conversion involves constructing a box-shaped extension on a slanted roof, resulting in walls that form a right angle with the floor. This clever addition not only increases the available headspace but also expands the overall floor area.

Estimated Cost

Starting from £50K

Double Mansard Loft Conversion

A double Mansard loft conversion is the most spacious and extensive option available. This type of conversion involves constructing both a front and rear Mansard, adding an entire new storey to the property.

Estimated Cost

Starting from £60K

L-Shaped Mansard Loft Conversion

Create a truly unique living space with an L-shaped mansard loft conversion. This innovative design combines the elegance of a mansard roof with the versatility of an L-shaped layout, offering abundant floor space and a distinctive architectural feature for your home.

Estimated Cost

Starting from £70K

Hip to gable Loft Conversion

A hip to gable loft conversion is well-suited for end of terrace and detached houses. This type of conversion involves altering the inwardly slanted end roof of the house to create a vertical wall. By doing so, the original hip roof is transformed into a gable roof.

Estimated Cost

Starting from £65K

L-Shaped Loft Conversion with full back addition

An L-shaped Mansard conversion involves the construction of two mansard builds that are interconnected. Typically, one Mansard is built on the rear outrigger roof, while the other is constructed on the main roof, resulting in the distinctive L-shape of this type of conversion.

Estimated Cost

Starting from £75K

Half L-Shaped Loft Conversion

In an L-shaped loft conversion, two dormers are constructed and joined together. One dormer is built as a flat roof extension over the main portion of the roof, while the other dormer is positioned at the rear, covering half of the roof area. This creates a unique half L-shape when observed from above.

Estimated Cost

Starting from £65K

L-Shaped Loft Conversion With Balcony

An L-shaped loft conversion involves the construction and connection of two dormers. One dormer is built over the main part of the roof, while the other dormer is positioned at the rear, covering one half of the roof area. Additionally, the other half of the roof is transformed into a balcony, adding an outdoor space to the conversion.

Estimated Cost

Starting from £70K

Kitchen Extensions

Small Rear Flat Roof

This conversion builds a terrace kitchen extension with a flat roof. They are ideal for terraced or semi-detached homes. Flat roofs are more cost-effective. These usually extend the ground floor space of the outrigger.

Estimated Cost

Starting from £45K

Large Rear Pitched Roof

This rear extension has a sloping roof for better aesthetics. Skylights bring in more natural light, and bi-fold doors open onto the garden. The larger floor space offers more living space options.

Estimated Cost

Starting from £60K

Large Rear Flat Roof

It is a rear extension with a flat roof, which is economical in design. Using skylights will bring plenty of natural light to the new addition. Bi-fold doors seamlessly connect the addition to the garden.

Estimated Cost

Starting from £60K

Large Rear Single Pitched Roof

Double the visual impact with the roof design for your rear extension. It is both modern and suitable for period architecture. Entertain your guests in an open-plan kitchen or a perfect orangery with oversized skylights.

Estimated Cost

Starting from £70K

Large Rear Double Pitched Roof

This extension offers a more polished roof design, which blends seamlessly with existing period architecture. With extensive glazing, you can create a quiet sunlit sitting room for your kitchen well-connected to the outdoors.

Estimated Cost

Starting from £65K

Small Side Infill Flat Roof

Harmonise your Victorian floor plan with this easy extension. This infill can extend your kitchen or even become a utility room. Perfect for smaller properties, a flat roof ensures less build work.

Estimated Cost

Starting from £50K

Medium side infill flat roof

Utilise the awkward space of the side return of your Victorian home to add extra space to the rear of the property. A flat roof with skylights offers natural light and even head height.

Estimated Cost

Starting from £60K

Large Side Infill Flat Roof

It offers plenty more space for a larger kitchen, a bathroom, a home office, or a garden room. Increase your Victorian home’s square footage by unifying the old configuration for a practical, livable space.

Estimated Cost

Starting from £75K

Small Side Infill Pitched Roof

Incorporate a sloping roof into your infill to complement your home’s period architecture. Skylights offer natural light and extend your kitchen without using any main garden space. Ideal for small side returns.

Estimated Cost

Starting from £50K

Medium Side Infill Pitched Roof

Extend your kitchen in style or create a small dining area. It offers a versatile space by seamlessly integrating redundant space at the back of your Victorian home. A pitched roof enhances the aesthetics.

Estimated Cost

Starting from £60K

Large Side Infill Pitched Roof

Transform your kitchen area with an open-plan layout. Harness more natural light with skylights and create a bigger kitchen, dining area, bathroom, utility room, home office, home gym, or lounge area.

Estimated Cost

Starting from £75K

Rear & Small Side Infill Pitched Roof

Fill in the side return and build a small rear extension at the same time. Add double the space and save money. A pitched infill roof and flat rear roof prevents a boxed-in design.

Estimated Cost

Starting from £75K

Rear & Medium Side Infill Pitched Roof

Add more square footage to your period home by extending to the side and the rear. Our pitched infill roof enhances visual appeal, and the flat rear roof is practical and modern.

Estimated Cost

Starting from £70K

Rear & Large Side Infill Pitched Roof

A larger Victorian property can boost its value with a more usable floor area. Make use of the underutilised side return for infill and create a rear addition in one project.

Estimated Cost

Starting from £80K

Small Wrap-around Single Pitched Roof

Join your infill and rear extensions for a wrap-around. The single-pitched roof makes the addition visually appealing. Skylights create a light-filled large space perfect for open-plan living.

Estimated Cost

Starting from £65K

Medium Wrap-around Single Pitched Roof

This extension offers two living spaces or one large kitchen area with plenty of room for modern entertaining. The single-pitched roof design saves money while maximising style with natural light from skylights.

Estimated Cost

Starting from £75K

Large Wrap-around Single Pitched Roof

Discover optimal floor space for your ground floor with a roof design that is not too tricky but big on style. Create multiple rooms or living areas that blur into the garden with oversized glazed doors.

Estimated Cost

Starting from £95K

Small Wrap-around Double Pitched Roof

Tiny space? No worries. The double-pitched roof design makes up for the small size with a space-maximising look. Go bold on elegance and create a stunning extension that creates uniform space at your home’s rear.

Estimated Cost

Starting from £65K

Large Wrap-around Double Pitched Roof

Sunlit rooms or one big living area for all your loved ones to gather. Explore all the possibilities with this extension. Reconfigure your floor plan or extend your kitchen for the ultimate open-plan experience.

Estimated Cost

Starting from £80K

Medium Wrap-around Double Pitched Roof

A polished look for your period home extension will only increase its value. The double-pitched roof wrap-around can blend in or stand out as you wish. Plenty of room for entertaining or family entertainment.

Estimated Cost

Starting from £95K

Small Wrap-around Flat Roof

Functional spaces with a practical design. Give your wrap-around a minimalist profile. Join a side infill with a rear extension to create a unified space. Incorporate more glazing for space-enhancing ambience.

Estimated Cost

Starting from £50K

Medium Wrap-around Flat Roof

Cost-effective design with cleaner lines for contemporary spaces. An infill and a rear extension join to form a wrap-around. Extend your kitchen and add a stylish dining room well-connected to the outdoors.

Estimated Cost

Starting from £95K

Large Wrap-around Flat Roof

This addition combines a side return with a rear extension. The flat roof is economical to build, and the skylights bring in plenty of natural light. Maximise your extension capacity for spaces that set you free.

Estimated Cost

Starting from £90K

Frequently Asked Questions

Built Around Exceptional Client Experience

01.

WHAT ARE THE DIFFERENT TYPES OF HOME EXTENSIONS AND LOFT CONVERSIONS?

There are several popular options for expanding your home in South East London. For extensions, the most common types are single-storey rear extensions, double-storey extensions, side-return extensions, and wrap-around extensions. Each adds significant living space and can be tailored to your layout and budget.

For loft conversions, the main types are Velux (rooflight), dormer, hip-to-gable, and mansard conversions. The right choice depends on your roof structure, permitted development rights, and how much headroom you currently have.

At Space Up, we assess your property and recommend the most cost-effective solution — contact us for a free consultation.

02.

HOW TO ESTIMATE BUILDING COSTS FOR AN EXTENSION?

Building costs in South East London typically depend on three factors: the size of the project, the specification of finishes, and site-specific conditions such as access, ground conditions, and party wall requirements.

As a general guide, a single-storey rear extension starts from around £2,000–£2,500 per m², while a loft conversion typically starts from £35,000–£50,000 depending on type and size. These figures include labour and materials but exclude VAT, architectural fees, and planning costs.

The most accurate way to estimate your project is to get a detailed quote. SpaceUp provides free, no-obligation surveys across Greenwich, Lewisham, Bromley, Southwark, and surrounding areas.

03.

DO I NEED PLANNING PERMISSION FOR A HOME EXTENSION OR LOFT CONVERSION?

Many home extensions and loft conversions in South East London can be built under Permitted Development (PD) rights, meaning no formal planning application is required. For example, a single-storey rear extension of up to 4 metres (detached) or 3 metres (semi/terraced) typically falls within PD limits.

However, planning permission is required if your property is in a conservation area, is a listed building, or if the proposed works exceed PD thresholds. Double-storey extensions and mansard loft conversions almost always require a full planning application.

At Space Up, we handle the entire planning process on your behalf — from initial assessment to submission — so you don’t have to worry about the paperwork.

04.

HOW LONG DOES A HOME EXTENSION OR LOFT CONVERSION TAKE TO COMPLETE?

Timelines vary depending on the scope of works. As a general guide:

— Single-storey rear extension: 10–14 weeks on site

— Double-storey extension: 16–20 weeks on site

— Dormer or hip-to-gable loft conversion: 8–12 weeks on site

— Full home refurbishment: 12–24 weeks depending on scale

These timelines don’t include the design and planning stage, which typically adds 8–16 weeks before works begin. SpaceUp provides a detailed project programme before any works start, so you always know exactly what to expect and when.