Garden Room Extensions vs Conservatories

When looking to add extra living space to your North London home while connecting to your garden, two popular options emerge: traditional conservatories and modern garden room extensions. Whilst both add valuable space and garden connections, they differ significantly in construction, usability, cost, and planning requirements. This comprehensive guide explores the key differences to help you choose the right option for your property and lifestyle.

Understanding Conservatories

Conservatories are glazed structures attached to houses, typically with more than 75% glass walls and a glass or polycarbonate roof. They're designed primarily as transparent, light-filled spaces creating strong connections to gardens.

Traditional Construction

Conservatories typically feature lightweight dwarf walls (half-height brick or low walls), extensive glazing forming walls, glass or polycarbonate roofs, and lightweight frames in uPVC, aluminium, or timber. They're often built on simple foundations, sometimes pad foundations rather than full perimeter foundations required for traditional extensions.

Types of Conservatories

Several conservatory styles suit different properties. Victorian conservatories feature ornate details with bay fronts and decorative ridge cresting. Edwardian conservatories offer square or rectangular footprints maximising usable floor space. Lean-to conservatories provide simple, cost-effective designs working well on bungalows or where height is restricted. Gable-fronted conservatories create impressive, tall spaces with front glass panels extending to the roof apex.

Pros of Conservatories

Conservatories offer lower construction costs than garden room extensions, typically ranging from £8,000-£25,000 depending on size and specification. They create bright, light-filled spaces with strong garden connections. Installation is relatively quick, often completed within weeks. They may not require planning permission as they can often be built under permitted development rights. Conservatories add property value and appeal, particularly to buyers seeking garden connections.

Cons of Conservatories

Temperature control is the primary challenge - conservatories often overheat in summer and feel cold in winter despite heating. Glass roofs amplify this problem. They're typically less energy-efficient than solid-roofed extensions. Many owners find conservatories unusable for parts of the year due to temperature extremes. Privacy can be limited with extensive glazing. Furniture and fabrics can fade due to strong sunlight. Cleaning extensive glass areas requires regular maintenance.

Understanding Garden Room Extensions

Garden room extensions are solid-roof extensions with conventional walls and windows, built to the same standards as house extensions. They're effectively additional rooms that happen to face gardens.

Modern Construction

Garden room extensions feature solid insulated roofs meeting building regulations thermal standards, conventional insulated cavity or timber-framed walls, regular window and door openings rather than wall-to-ceiling glass, and standard foundations to building regulations standards. They're built to the same thermal and structural standards as house extensions.

Design Flexibility

Garden rooms offer extensive design flexibility. They can incorporate large sliding or bi-fold doors creating garden connections when open. Roof lights or lantern lights bring natural light while maintaining thermal performance. They can be designed in any architectural style from traditional to contemporary. Internal finishes match main house standards rather than being distinctly different conservatory spaces.

Pros of Garden Room Extensions

Garden rooms are usable year-round with proper heating and insulation performing like regular rooms. They offer better thermal efficiency, reducing heating costs and environmental impact. Privacy and security typically exceed conservatory standards. They integrate architecturally with houses more successfully than conservatories. Furniture, flooring, and decoration options match those in main houses without concerns about fading or temperature damage. They typically add more property value than conservatories as they're considered proper living space.

Cons of Garden Room Extensions

Garden room extensions cost significantly more than conservatories, typically £20,000-£60,000 depending on size and specification. They're more likely to require planning permission than conservatories. Construction takes longer, often several months. They may feel less connected to gardens than fully glazed conservatories unless extensive doors and windows are incorporated. Building control approval is required, adding time and cost to projects.

Planning Permission and Building Regulations

Regulatory requirements differ significantly between conservatories and garden room extensions.

Conservatories

Conservatories meeting certain criteria can be built under permitted development rights without planning permission. These criteria include extending beyond the rear wall of the original house by no more than specified limits (three metres for terraced houses, four metres for detached houses), maintaining total coverage of extensions and outbuildings below 50% of the land around the original house, and keeping maximum height below four metres or eaves height below three metres.

Conservatories in conservation areas or on listed buildings typically require planning permission. Even when planning permission isn't needed, conservatories meeting specific thermal separation criteria (physically and thermally separated from the house with independent heating) may be exempt from some building regulations requirements. However, regulations covering structural safety, drainage, and electrical safety still apply.

Garden Room Extensions

Garden room extensions can sometimes be built under permitted development rights if they meet the same dimensional criteria as conservatories. However, they must fully comply with building regulations including thermal performance, structural design, damp-proofing, drainage, and electrical safety. This requires building control approval and inspections during construction.

In conservation areas or on listed buildings, planning permission is typically required. Garden rooms significantly extending beyond specified limits need planning permission regardless of location.

Cost Comparison

Understanding full costs helps you budget appropriately.

Conservatory Costs

Basic uPVC conservatories start from around £8,000 for small lean-to designs. Mid-range conservatories with better glazing and finishes cost £15,000-£20,000. High-end conservatories with timber frames, quality glazing, and sophisticated designs can exceed £25,000-£30,000.

Additional costs include groundworks and foundations, electrical work including lighting and heating, flooring typically tile or similar hard finishes, heating if required, and blinds or shading solutions to manage temperature.

Garden Room Extension Costs

Garden room extensions typically cost £1,500-£2,500 per square metre depending on specification and complexity. A modest 15 square metre garden room might cost £25,000-£40,000. Larger or more sophisticated designs can easily exceed £50,000-£60,000.

Costs include foundations and groundworks, building the structure with walls and roof, windows and doors including bi-folds if desired, electrical and heating installation, insulation to building regulations standards, plastering and decorating, and flooring.

Usability and Functionality

How you intend to use your new space influences which option suits you better.

Conservatories

Conservatories work well as sitting rooms for enjoying garden views, dining spaces for casual meals, plant rooms for gardening enthusiasts, and occasional entertainment spaces in good weather. They're less successful as home offices due to temperature extremes and glare, year-round dining rooms unless very well-specified with heating and shading, or playrooms where temperature control matters for children's comfort.

Garden Room Extensions

Garden rooms function well as living room extensions, open-plan kitchen diners, home offices requiring year-round comfort, guest rooms or bedroom extensions, playrooms and family spaces, or any use requiring regular, comfortable occupation regardless of weather.

Thermal Performance Solutions

Modern solutions help address traditional conservatory thermal problems.

Solid Conservatory Roofs

Replacing glass or polycarbonate roofs with insulated solid roofs transforms conservatory performance. These lightweight tiled roofs incorporate insulation meeting building regulations standards while maintaining conservatory aesthetics. Roof lights bring natural light while insulated sections provide thermal performance. This upgrade costs £3,000-£7,000 depending on conservatory size but significantly improves year-round usability.

Solid conservatory roofs blur the distinction between conservatories and garden room extensions, creating hybrid spaces with conservatory glazed walls but extension-quality thermal performance.

Advanced Glazing

Modern glazing technologies improve conservatory performance. Low-E glass reflects heat back into conservatories in winter while reducing solar gain in summer. Self-tinting glass automatically adjusts to manage solar gain. Argon-filled triple glazing significantly improves thermal performance. These upgrades add cost but deliver better usable spaces.

Design Considerations

Good design maximises benefits of both options.

Orientation

Consider how your extension faces affects usability. South-facing conservatories receive maximum sun, risking overheating but requiring less heating in winter. North-facing conservatories stay cooler but require more heating. East-facing spaces enjoy morning sun while west-facing ones get afternoon and evening light.

Garden room extensions can be designed to manage orientation challenges through window sizing and positioning, shading devices, and appropriate glazing specifications.

Garden Connections

Both options should maximise garden connections. Large sliding or bi-fold doors create seamless transitions between inside and outside. Multiple doors can open entire walls to gardens in good weather. Even in garden room extensions, generous glazing towards gardens maintains visual connections while solid roofs and side walls provide thermal performance.

Architectural Integration

Successful conservatories and garden rooms complement existing architecture rather than appearing as obvious additions. Match or complement external materials to your house. Consider roof pitch and details to harmonise with existing rooflines. Ensure proportions work with the main house and don't overwhelm it.

Making Your Decision

Several factors help determine which option suits you best.

Choose conservatories if you want maximum light and garden connection, have a more modest budget, desire quick installation with minimal disruption, or specifically want a greenhouse-like space for plants or sitting in natural light.

Choose garden room extensions if you want year-round usable living space, plan to use the space as a home office or living area, prioritise thermal efficiency and running costs, have budget for higher initial investment, or want space that functions like a regular room rather than seasonal space.

Consider hybrid solutions like conservatories with solid roofs if you want conservatory aesthetics with better thermal performance, have an existing conservatory you want to make more usable, or desire significant glazing for light while avoiding temperature extremes of glass roofs.