Minimum Space Standards for New Homes (2025)

15 Mar

Minimum space standards are a core regulatory and design consideration for new residential development across England, and particularly in London. These standards ensure that new homes are functional, safe, and comfortable—supporting residents’ long-term health, well-being, and adaptability.

This updated 2025 guide is essential reading for architects, planners, developers, and housing providers, offering a full breakdown of the Nationally Described Space Standard (NDSS), London’s enhanced benchmarks, and relevant design and planning guidance, especially for residential conversions and HMOs.

📐 What Are Minimum Space Standards?

Minimum space standards set out the gross internal floor area (GIA) and bedroom dimensions required for new dwellings based on occupancy, layout, and number of storeys. They were introduced to:

Prevent substandard housing
Improve design quality
Promote long-term adaptability
Reduce overcrowding

The NDSS, first introduced in 2015 and updated in 2025, is a nationally applicable benchmark for all new homes, whether through new build or conversion (subject to local authority adoption via planning policy). The London Plan 2021 builds upon these standards with best practice guidance, reflecting the city’s intensified housing pressures.

Applicability of the Standards

The standards apply to:

New-build self-contained residential units (Class C3)
Conversions to residential dwellings
Prior approval conversions (where adopted by local policy)
Registered social and affordable housing schemes
Most planning applications in London (via the London Plan)

Minimum Gross Internal Areas (GIA) by Dwelling Type

    Type of dwelling
    Minimum gross internal floor area (GIA) and storage (m²)
    London best practice*
  


    Number of bedrooms
    Number of bedspaces
    1 storey
    2 storey
    3 storey
    Built-in storage
    GIA
    Built-in storage
  

    1b
    1p
    39/37**
    
    
    1
    +4
    +0.5
  

    2p
    50
    58
    
    1.5
    +5
  

    2b
    3p
    61
    70
    
    2
    +6
  

    4p
    70
    79
    86
    2.5
    +7
  

    3b
    4p
    74
    84
    90
    2.5
    +10
  

    5p
    86
    93
    99
    +11
  

    6p
    95
    102
    108
    +12
  

    4b
    5p
    90
    97
    103
    3
    +11
  

    6p
    99
    106
    112
    +12
  

    7p
    108
    115
    121
    +13
  

    8p
    117
    124
    130
    +14
  

    5b
    6p
    103
    110
    116
    3.5
    +12
  

    7p
    112
    119
    125
    +13
  

    8p
    121
    128
    134
    +14
  

    6b
    7p
    116
    123
    129
    4
    +13
  

    8p
    125
    132
    138
    +14
  

* In addition to the national space standards, the Mayor of London introduced “best practice” guidance urging for more space for London residents.
** Studio dwellings for 1 person with a shower room may be reduced to 37m² (otherwise 39m²).

⚙️ Technical Requirements for Compliance

To meet the NDSS (and by extension, the London Plan D6 standard), all new homes must satisfy the following:

Single bedrooms must be at least 7.5m² (and 2.15m wide).
Double/twin bedrooms must be at least 11.5m² (minimum width 2.75m for the main bedroom, 2.55m for others).
Ceiling heights must be a minimum of 2.3m for at least 75% of the GIA. The London Plan (Policy D6) encourages a higher standard of 2.5m for at least 75% of the Gross Internal Area to improve natural daylight and ventilation, but this is not a mandatory requirement.
Built-in storage must meet the minimum figures in the table above (excluding kitchen cupboards).
Areas with headroom below:
- <1.5m are excluded from GIA unless used for storage.
- 900mm–1.5m are counted at 50% (if storage-only).
- <900mm are not counted at all.
Wardrobes may count towards the GIA only if they don’t reduce usable floor area below minimum thresholds.

Minimum Bedroom Sizes in HMOs (Under the London Plan and Housing Acts)

For shared housing (Use Class C4 or sui generis HMOs), bedroom standards differ and are enforced via both licensing and planning controls, particularly in London boroughs like Enfield:

Single adult (shared kitchen) 6.51
Two adults (shared kitchen) 10.22
Children under 10 years old4.64

These are planning and licensing thresholds. Some local authorities may impose higher amenity standards through SPDs or licensing schemes.

📌 Importance of Adhering to Minimum Standards

Functionality and Comfort: Every dwelling must support the basic functions of daily life—sleep, hygiene, cooking, dining, socialising, working, and storage.
Adaptability: Well-designed spaces accommodate changing needs: work-from-home areas, family growth, or accessible features.
Health and Well-being: Proper space improves natural daylight, reduces overcrowding, enhances mental health, and supports good indoor air quality.
Sustainability and Longevity: Compliant homes are more resilient to future policy changes, more marketable, and better aligned with lifetime homes principles.

👷 Planning and Design Advice

Whether you're designing a new-build scheme, converting under Class MA, or submitting for full planning in Greater London:

Reference local plan policies (e.g. Enfield DMD 8, 9, 10 for design, spacing, and amenity).
Use a measured survey to avoid errors in net-to-gross calculations.
Validate GIA with technical drawings—include section cuts for ceiling height verification.
For HMO conversions, overlay space standards and licensing criteria to avoid non-compliance post-permission.

🧭 Final Thoughts

The minimum space standards remain one of the most important tools in ensuring homes meet the needs of residents—not just at point of sale, but throughout their life cycle.

At Bashkal, we advise developers on optimising unit layouts, resolving compliance risks, and submitting applications that hold up to scrutiny.