Basement and Cellar Conversions in Manchester and Greater Manchester

Cellar Conversion Services Across Greater Manchester

Victorian and Edwardian houses across Manchester, Stockport, and the surrounding areas were often built with cellars. Coal storage, food storage, servant quarters. Now most sit empty, damp, and full of junk. But that space has potential.

A cellar conversion adds usable floor area to your home without extending the building or eating into your garden. In areas where property prices are high and gardens are small, converting a cellar can be one of the smartest investments you make. The space already exists. It just needs making habitable.

Cellar conversions are more complex than loft conversions or extensions. Waterproofing is critical. Ventilation needs careful planning. Access can be tricky. But done properly, you get a unique space with great sound insulation and stable temperatures year-round.

Do You Have a Cellar?

Not all houses have cellars, and not all cellars are suitable for conversion. Here's what we look for:

Head Height

Building Regulations require minimum 2.1 metres floor to ceiling for habitable rooms. Many Victorian cellars are around this height already. If yours is lower, underpinning can increase head height by lowering the floor, but this adds significant cost and complexity.

Access

You need a proper staircase, not just a hatch and ladder. Many cellars have steep, narrow stairs that need replacing. Internal access from the hallway is ideal. External-only access via coal chute isn't practical for regular use.

Damp and Water Ingress

Most unconverted cellars are damp. That's normal and doesn't mean conversion is impossible. We assess the source of moisture and design appropriate waterproofing. Active water ingress from high water tables needs different treatment than general dampness from the surrounding soil.

Structural Condition

Brick walls and floors need checking for stability. Old houses can have settlement issues. We survey the structure and advise on any remedial work needed before conversion.

Waterproofing and Tanking

Waterproofing is the most important part of any cellar conversion. Get it wrong and you'll have ongoing damp problems. Get it right and your cellar stays dry for decades.

There are three main approaches to cellar waterproofing in the UK:

Type A: Tanking

A waterproof barrier applied directly to walls and floor. Cementite slurry, bitumen, or specialist tanking membranes. The barrier stops water getting through. Works well when water pressure is low and walls are in good condition. Relatively affordable but relies on the tank remaining intact. Any cracks or damage can let water in.

Type B: Structurally Integral

The structure itself is waterproof. Used mainly in new build basements with reinforced concrete designed to be watertight. Not usually applicable to cellar conversions in existing houses.

Type C: Drained Protection

A cavity drain membrane system. Dimpled plastic membrane on walls and floor creates a gap. Any water that gets through drains down behind the membrane to a sump pump, which pumps it away. The most reliable solution for cellars with significant water pressure. More expensive but doesn't fight the water, just manages it. The system we recommend for most conversions.

We often combine approaches. Type A tanking to floors with Type C cavity drain membranes to walls, for example. The right solution depends on your cellar's specific conditions. We survey properly and design waterproofing that works.

What Can You Use a Converted Cellar For?

Home Cinema

Cellars are perfect for home cinema rooms. No windows means complete darkness. Below-ground construction provides excellent sound insulation so you don't disturb neighbours or family upstairs. Stable temperatures year-round. Add acoustic treatment, comfortable seating, and a proper projector setup for the ultimate movie experience.

Home Gym

Heavy equipment in the basement won't damage upper floors. Noise from treadmills and weights doesn't travel upstairs. Space for full gym setup without compromising living areas. Good ventilation is essential for workout spaces, which we factor into the design.

Games Room or Bar

Pool table, darts, bar area. A dedicated entertainment space away from the main living areas. Soundproofing means late nights don't disturb sleepers upstairs. The cellar vibe actually suits a bar aesthetic really well.

Home Office

Quiet, separate workspace away from household distractions. Good for video calls since the acoustics tend to be excellent. Natural light is limited, so good artificial lighting is important. Some people find below-ground offices claustrophobic, so consider carefully if this suits you.

Playroom

Keep toys and mess out of the main living areas. Kids can be noisy without disturbing the whole house. Easy-clean flooring and wipeable walls make sense. Good lighting essential since there's limited natural light.

Extra Bedroom

Cellar bedrooms need careful thought. Building Regulations require means of escape in case of fire, which is challenging below ground level. Light wells or window wells can provide natural light and escape routes. Not suitable for main bedrooms but can work for occasional guest rooms or teenager dens with proper planning.

Utility and Storage

If full conversion isn't in the budget, even a basic tanking job transforms a damp cellar into dry storage or utility space. Wine storage (cellars are naturally cool), washing machine and tumble dryer, general household storage. Much more useful than a wet hole you can't use.

Planning Permission for Cellar Conversions

Converting an existing cellar to habitable space usually doesn't need planning permission. You're not extending the building or changing its external appearance. The work is internal.

However, you will need planning permission if:

• You're excavating to create a new basement where none exists
• You're extending an existing cellar beyond the building's footprint
• You're creating a separate dwelling (not just a room in your house)
• You're adding external light wells that change the appearance
• Your property is listed (Listed Building Consent required)
• You're in a Conservation Area and the external appearance changes

We check requirements for your specific property and handle any applications needed. For straightforward conversions, a Lawful Development Certificate provides confirmation that the work is permitted.

Building Regulations for Cellar Conversions

All cellar conversions creating habitable space need Building Regulations approval. Key requirements include:

Structural Stability

Any underpinning or structural alterations need engineer design. Existing walls and floors assessed for adequacy. New openings or staircase positions may need steel support.

Fire Safety

This is often the trickiest part. Cellars used for habitable purposes need a protected escape route or suitable fire escape window/door. Bedrooms below ground level need careful consideration. Fire doors, detection systems, and escape routes all specified based on the planned use.

Ventilation

Below-ground rooms need mechanical ventilation since natural ventilation through windows is limited. Extract ventilation at minimum, often full mechanical ventilation with heat recovery (MVHR) for comfortable conditions.

Damp Proofing

Waterproofing design submitted and approved. Building Control want to see that damp will be controlled permanently.

Insulation

Walls and floor insulated to meet thermal requirements. Often done inside the waterproofing membrane.

Ceiling Height

Minimum 2.1 metres for habitable rooms. Lower heights acceptable for storage or utility use.

Electrics

All electrical work Part P compliant. Sump pumps need reliable power supply with battery backup or alarm.

We handle all Building Regulations applications and coordinate inspections throughout the project.

The Cellar Conversion Process

1. Survey and Assessment

   We inspect your cellar thoroughly. Measure dimensions, check head height, assess damp levels, survey structure, and discuss what you want to achieve. You'll know if conversion is feasible and what's involved.

2. Design and Specification

   We design the waterproofing system, plan the layout, specify ventilation, and work with structural engineers if underpinning or structural alterations are needed. Drawings prepared for Building Regulations.

3. Quotation

   Detailed fixed-price quote covering all work. Waterproofing, drainage, electrics, ventilation, insulation, plastering, flooring, and finishing. Everything included.

4. Building Regulations Approval

   We submit applications and obtain approval before starting work. Any structural calculations and waterproofing designs approved.

5. Preparation and Clearance

   Cellar cleared out. Old finishes removed. Walls and floor prepared for waterproofing. Any structural work or underpinning completed.

6. Waterproofing

   Membrane system installed to walls. Floor drainage and sump installed. Pump fitted and tested. This is the critical stage that determines long-term success.

7. First Fix

   Electrical wiring, plumbing if required, ventilation ducting installed. Stud walls built out from membranes ready for insulation and boarding.

8. Insulation and Dry Lining

   Insulation fitted between studs. Plasterboard fixed. Ready for plastering.

9. Plastering and Second Fix

   Walls and ceiling skimmed. Sockets, switches, lights fitted. Doors hung. Skirting and architraves.

10. Finishing and Handover

    Decoration, flooring, final finishes. Building Control final inspection. Sump pump commissioned and demonstrated. Handover with all documentation and warranties.

Underpinning for Extra Head Height

If your cellar has less than 2.1 metres head height, underpinning can lower the floor to create more space. This is a major undertaking.

Underpinning involves excavating beneath existing foundations in sections, then pouring new concrete deeper down. The existing walls are temporarily supported while each section is done. It's slow, expensive, and needs careful engineering.

Typical costs for underpinning are significant and can double or triple the overall conversion cost. We advise honestly whether underpinning makes financial sense for your property or whether the money would be better spent on other improvements.

Cellar Conversions Across Greater Manchester

Victorian and Edwardian houses with cellars are found throughout Greater Manchester:

South Manchester areas like Chorlton, Didsbury, Levenshulme, and Heaton Moor have lots of Victorian terraces with cellars. Many were originally coal cellars with external access. The terraces in Prestwich, Whitefield, and around Bury also commonly have cellars. Not all properties have them, but if yours does, it's worth investigating the potential.

Why Choose Renovate for Your Cellar Conversion?

• Waterproofing expertise: We use proven systems that keep cellars dry long-term
• Complete service: Design, Building Regs, waterproofing, and full fit-out from one company
• Structural experience: We work with engineers on complex underpinning projects
• Fixed prices: Detailed quotes with everything included. No surprises
• Building Regs handled: We manage applications and inspections
• Guaranteed work: Waterproofing systems with manufacturer warranties plus our 12-month workmanship guarantee
• Honest advice: We'll tell you if conversion doesn't make sense for your cellar