House Extensions

Basement & Cellar Conversions in Surrey & Hampshire

Unlock hidden space beneath your home with a professionally tanked and waterproofed basement conversion.

Below-Ground Living Space

Space You Didn't Know You Had

If your Surrey or Hampshire home has an existing basement or cellar, you are sitting on one of the most valuable untapped spaces in your property.

A professionally converted basement can add a completely new floor to your home, without touching your garden or altering your roofline, and deliver a significant increase in both living space and property value.

Hogs Back Builders has extensive experience in basement and cellar conversion projects, from simple cellar waterproofing and conversion into storage or utility rooms, through to fully fitted habitable rooms used as home cinemas, gyms, playrooms, guest bedrooms or home offices.

Two Story Side Extension

What Can a Basement Conversion Include?

  • Home cinema or entertainment room
  • Gym or fitness studio
  • Home office or study
  • Additional bedroom or guest suite
  • Children's playroom
  • Wine cellar or storage room
  • Utility and laundry room
  • Self-contained annexe or rental accommodation

What's Involved

Basement Conversion Essentials

  • Tanking & Waterproofing

    Cavity drain membranes, cementitious tanking, or combined systems to keep your basement permanently dry.

  • Mechanical Ventilation

    MVHR or extract systems ensuring fresh air circulation and compliance with Part F.

  • Lighting Design

    Layered artificial lighting to make a below-ground room feel bright and inviting.

  • Heating & Insulation

    Insulated walls, UFH or radiators, and Gas Safe heating connections.

  • Access & Egress

    Safe staircase design and fire-escape planning compliant with Part B.

  • Building Control

    Full structural calcs, fire safety, and building regulations sign-off included.

Our work

Recent projects

Where we work

Across Surrey & Hampshire

Hogs Back Builders is based near Farnham on the Surrey/Hampshire border and operates throughout a wide area of both counties. Over nearly two decades of trading, we have built an extensive network of completed projects and satisfied clients from Woking in the north-east to Petersfield in the south, and from Guildford in the east to Andover in the west.

We take on projects of all sizes across our service area and aim to be the local building company of choice in every community we serve. The main towns and areas we cover are listed below.

Areas we cover

Want to Talk to Us About Your Project?

We'd love to hear about your plans. Call us on 01483 662408 or 07957 861230 for a free, no-obligation quote and a free site visit, or use the enquiry form on our Contact page.