Contact Us

We would love to hear from you about your intended project.

Use the form on the right to contact SPACIOUS about an initial consultation or email us at:



54 George's Street Lower
Dublin, County Dublin,

01 5585205

Award Wining Architects based in Monkstown, Co.Dublin and working in all surrounding counties.

Specialising in sensitive contemporary design for domestic extensions, renovations, new-build houses and interior design.  We also design and build custom joinery.

RIAI registered architects, project managers & interior designers

Dublin Architecture Blog

Hofler Architects Dublin  - Our Blog of our news and views.

Filtering by Tag: Home Renovation

New Building Regulations energy rules for home renovations and extensions, 2019.

Paul Mulhern

“A follows D” - A recent major renovation and extension by Spacious Architects that brought an existing D rated house up to a BER A standard.

House owners planning to undertake major renovations or extensions will be required to ensure that the whole dwelling will meet the higher energy rating (BER) of B2 upon completion under new building regulations.

The new rules will come into effect from November 2019, and will also require all new homes to become nearly zero energy buildings (NZEB). That will require them to have a BER of A2, - twice as energy efficient as the current minimum required rating for new builds of A3.

Where more that 25 per cent of the surface of the building is undergoing renovation or an extension there will be a requirement that the whole building should achieve an energy efficiency of B2 or cost optimal level.

On November 1, amendments to Part L and Part F of the building regulations (relating to energy efficiency and ventilations) for new residential dwellings and dwellings getting major renovations come into effect. The Government said the rules will be subject to transition arrangements to allow flexibility to developers.

Requirements for major renovation of domestic buildings

For existing buildings, it is proposed that major renovation is typically activated under the following circumstances, where the work affects greater than 25% surface area of the existing dwelling:

  • External Wall Renovation, external or internal insulation

  • External Wall & Window Renovation

  • External Wall & Roof Renovation

  • External Wall & Floor Renovation

  • New Extension

The cost optimal level is a primary energy performance of less than 125 kWh/m2/yr (B2 BER) when calculated using DEAP or upgrade of roof insulation and heating system. The Cost Optimal Study was updated in 2018.

Painting, replastering, rendering, reslating, cavity wall insulation are not considered major renovation works.

Energy upgrade works to the house pictured above included:

Link: Irish Times article

Irish Times feature - As Green as a Period House can be.

SPACIOUS - Registered architects and designers

T: 01-5585205 | M: 089-2447264

George's Street Studios, First Floor, 53/54 George's Street Lower, Dun Laoghaire, Co. Dublin. | | Instagram