Duplex (two-storey)

Duplex unit reference scheme

Two stacked volumetric modules forming a two-storey dwelling with internal stair — the same production line, twice the plan, one lift cycle per level.

Typology: Duplex (two-storey)
Application: Peri-urban and estate infill
Status: Design study
Market position: Beachhead market 03

01Overview

The duplex is the vertical extension of the simplex. Two modules, one atop the other, share a precast stair cast from the same production environment.

It is the reference unit for higher-density housing programmes and staff estates where plot ratios reward stacking without moving to full apartment blocks.

02The constraint

A two-storey dwelling introduces vertical alignment, waterproofing at the module interface and a stair that has to be produced and placed to the same tolerances as the walls.

03The response

Modules are cast with matched connection details top and bottom. The precast stair drops in as one element. The joint between levels is detailed and tested in the factory, not improvised on site.

04Scope of work

Design for manufacture
Module manufacture and precast stair
Transport, lifting and stacking
Interface waterproofing and services connection

05Specification

Unit: Two stacked modules — 6.05 × 3.25 × 3.035 m each
Levels: Two storeys, internal precast stair
Handling: 30 t rectangular lifting frame

06Collaborators

Scheme architect: Client appointment
Structural engineer: Registered professional appointment

Design study — no client appointment

07Gallery

Completed duplex dwellings arranged along a residential street. — Stacked modules, one internal stair, one handover

Visualisation — design study, not a delivered project

Building something like this?