New Zealand faces increasing demand for accessible housing that supports disability inclusion, ageing in place, and long-term usability and resilience. However, not all housing forms are equally suited to delivering accessible outcomes.

Current approaches can treat accessibility as a uniform requirement across typologies. This paper evaluates a differentiated and aggregated approach, one that recognises typological constraints while still delivering strong overall accessibility outcomes across developments.

An accessible dwelling at a minimum:

• Provides step-free access and entry
• Enables movement throughout primary living spaces (wider doorways and corridors)
• Includes a usable bathroom and toilet
• Supports bedroom access on the entry level (or with lift)
• Allows for future adaptation, such as the inclusion of grab rails, with minimal structural change

This aligns with Universal Design and Lifemark© principles and meets many of the requirements for a Lifemark© 3 Visitable certification.

3.1 Single-Level Dwellings

Capability: High (Best Practice Baseline)

Key advantages:

• No vertical circulation barriers
• Simplified structural design
• Lowest cost pathway to full accessibility

Strategic role: Benchmark typology for fully accessible housing supply.

3.2 Apartments (4+ Storeys)

Capability: High (System-Enabled Accessibility)

Key advantages:

• Lift-enabled vertical access
• Level access from street to dwelling
• Repeatable accessible layouts

Strategic role: Scalable delivery mechanism for accessible housing in urban environments that meet density requirements.

3.3 Two-Level Dwellings

Capability: Moderate (Conditional Accessibility)

Accessible when:

• Ground-floor bedroom and bathroom provided
• Step-free entry achieved

Limitations:

• Upper floor is inaccessible

Strategic role: Transitional typology; can contribute meaningfully if design is purposeful and accessibility is considered

3.4 Three-Level Townhouses

Capability: Low

Key issues:

• Vertical stacking of core functions
• Heavy reliance on stairs
• Limited retrofit potential

Strategic role: Density-driven typology with minimal accessibility contribution.

3.5 Three-Storey Walk-Up Apartments

Capability: Low

Key issues:

• No lift access
• Upper units inaccessible
• Building-wide design constraints limit the provision of accessible ground-floor unit designs
• Site planning (levels, parking, circulation) frequently reduces step-free access into ground-floor units

Strategic role: Should not be relied upon for accessibility outcomes.

4.3 Site Planning Implications

Developers can improve outcomes by:

• Clustering accessible typologies near transport and amenities
• Allocating ground-floor units strategically for accessibility
• Balancing typologies mix
• Using apartments as accessibility anchors within developments

A matrix-based approach enables:

• Outcome-based overview
• Typology-sensitive requirements
• Development-level accessibility targets
• Efficient allocation of cost and design effort

Policy should:

• Incentivise high-performing typologies
• Set minimum conditions for moderate typologies
• Recognise and offset low-performing typologies
• Understand and match supply with demand statistics for the area

• Accessibility is cost-effective when included from concept design stage
• Marginal cost is lowest in single-level and apartment typologies
• Retrofitting vertical circulation is prohibitively expensive
• A matrix approach avoids inefficient over-design in constrained typologies

Not all housing typologies can deliver equal accessibility outcomes, but developments can.

By shifting to a portfolio and matrix-based approach, New Zealand can:

• Increase accessible housing supply
• Maintain development feasibility
• Better align density with inclusion