Knowledge hub12 questions
Basements and below-ground space, answered plainly.
Basement construction, waterproofing and below ground space, done properly.
Basements and below-ground spaceStraight answers
What people ask us about basements and below-ground space.
Is my property suitable for a basement?
Suitability depends on planning, ground and water conditions, existing foundations, neighbours, utilities and access. Feasibility work sets out the main constraints before we develop a detailed layout.
Next We start with engineering and planning input for your actual site.
Can a basement extend beneath the garden?
This needs planning and engineering review specific to your property. Trees, retained planting, drainage, access and the effect on neighbours all need consideration.
Next We check current local policy rather than assume a permitted size or depth.
Can I add another basement level below an existing one?
Deeper excavation can significantly change the structural, water, access and planning risks. Existing basement drawings and approval records matter a great deal here.
Next We carry out a feasibility assessment before developing accommodation plans.
How is basement waterproofing designed?
It is a coordinated specialist design for the intended use and ground conditions. The construction method is designed in alongside it.
Structure, joints, penetrations, drainage and maintenance access all need to work together.
Next We identify the waterproofing designer, design responsibility and warranty terms.
Will a basement need pumps and backup systems?
That depends on the drainage and waterproofing design.
Where pumps are needed, we assess redundancy, alarms and power-loss response. We also plan ongoing access for servicing.
Next We explain how water is managed normally and if a failure happens.
How is neighbouring movement risk managed?
Engineering, temporary works, sequencing and monitoring are central to our approach. We never promise zero movement just because monitoring is installed.
Next We provide the monitoring plan and how trigger levels lead to action.
How is excavated material removed from a London terrace?
Access, conveyors, storage and collection are all planned around the street. The property itself shapes these arrangements too.
These logistics affect cost, programme and disruption to neighbours.
Next We show you the site logistics strategy before agreeing a programme.
Can a basement feel like a normal living floor?
Room proportions, light, ventilation, acoustics and the stair connection matter as much as finishes. We plan lightwells and rooflights alongside structure, privacy and water management.
Next We set a daylight and comfort brief for each proposed room.
Can a basement include a cinema, gym or wine room?
Each use needs its own structural, acoustic, ventilation and environmental requirements. A wine room and a gym should not share assumptions about temperature or humidity.
Next We define the equipment and operating conditions you need before design starts.
Can a swimming pool or spa be included?
A pool or spa needs specialist feasibility for loads, structure and water treatment. Humidity control, plant and maintenance access all need checking too.
We treat it as a separately defined specialist package.
Next Send us the space and budget so we can assess the specialist team needed.
What belongs in a basement shell package and what is fit-out?
We define the boundary explicitly for every package. Structure, waterproofing, drainage, slab, stairs, services and finishes can be allocated differently.
A shell price should never be compared with a fully finished living floor.
Next We agree a package inclusion schedule with clear interfaces.
What ongoing maintenance does a basement need?
We follow the actual waterproofing, drainage, pump and ventilation maintenance schedules.
Keep inspection access clear and keep service records. Warranty terms can depend on this maintenance being kept up.
Next We include basement systems in the handover and aftercare plan.
Next step
Ready to talk about basements and below-ground space?
Read more about how NU works. Or send us your project.