# Basement Construction in Northwood

Single-storey, double-storey and lightwell basement excavations under existing London homes. Delivered for Northwood (HA6), London, by HXL Construction under a single JCT contract, coordinated with London Borough of Hillingdon.

## Overview
HXL delivers basement construction in Northwood and across the wider London. Basement construction under existing London townhouses, semi-detached and detached homes is high-margin, technically demanding work that HXL routinely delivers. Single-storey excavations under footprint, double-storey schemes, lightwell and sub-pavement vault construction in conservation-area streets. All schemes include temporary-works design, structural propping, BS 8102-compliant waterproofing, and party wall coordination across all affected neighbours.

## Capability
- Single-storey basement excavation under existing footprint
- Double-storey basement schemes
- Lightwell and sub-pavement vault construction
- Temporary works and propping design
- BS 8102 Type C cavity-drainage waterproofing
- BS 8102 Type A and Type B tanked waterproofing
- Underpinning to existing foundations
- Party wall award coordination across all neighbours

## Northwood: local context
**Property stock.** 1930s Metroland detached and semi-detached homes, mock-Tudor stock, some period properties and contemporary rebuilds. Substantial plots characteristic of HA6.

**Planning and conservation.** Northwood Way Conservation Area and Rickmansworth Road Conservation Area. Article 4 directions apply in parts. Local planning authority: London Borough of Hillingdon.

**Typical scope in Northwood:**
- Wrap-around and rear extensions on 1930s detached homes
- Loft conversions (hip-to-gable, mansard)
- Basement excavations under single-storey footprint
- Whole-house refurbishments
- Conservation-compliant external works

## Process
01. **Survey & design** — Ground investigation, structural engineering design, party wall service, planning consent where the scheme falls outside permitted development.
02. **Excavation** — Underpin, install temporary works, excavate, remove spoil, construct retaining walls.
03. **Waterproofing & fit-out** — BS 8102 system installation, M&E first fix, plant install, second fix and finishes.
04. **Sign-off** — Structural sign-off, Building Control completion, waterproofing system warranty, 12-month workmanship warranty.

## FAQ
**Does HXL carry out basement construction in Northwood?** Yes. HXL delivers basement construction across Northwood (HA6) and the wider London, as a principal contractor under a single JCT contract.

**Who is the local planning authority for Northwood?** London Borough of Hillingdon. Northwood Way Conservation Area and Rickmansworth Road Conservation Area. Article 4 directions apply in parts.

**What properties does HXL work on in Northwood?** 1930s Metroland detached and semi-detached homes, mock-Tudor stock, some period properties and contemporary rebuilds. Substantial plots characteristic of HA6.

## Related
- Basement Construction (overview): https://hxlconstruction.co.uk/services/basement-construction
- Construction in Northwood: https://hxlconstruction.co.uk/areas/northwood

Contact: info@hxlconstruction.com · +44 7845 585147 · HXL Construction Ltd, 102 Vine Lane, Uxbridge, London UB10 0BE