Architect - Studio Red Architects 

Contractor - Halton Construction 

Photographer - Peter Grogan 

Project Type - Residential 

Date - 2014

Ecological Products Used 

  • Thermo Hemp
  • GUTEX Multitherm
  • SOLITEX UM Membrane
  • DAMMSTATT Cellulose Insulation 


This project involved a large family home to be built on a beautiful site sloping down to Lough Melvin, Leitrim.  The building is split into volumes – bedroom, living and leisure.  The volumes and materials are derived from simple agricultural buildings in order to bed into the landscape.

Ecological Provided

Ecological Building Systems provided extensive technical backup prior to this project going to the site.  Studio Red Architects consulted Ecological for guidelines relating to insulating the walls and the pitched roof, curved roof and masonry walls beside the swimming pool.

Following a short consultation session, Ecological Building Systems provided CPD presentations to the architects.  Peter Smith visited the site several times during the construction phase providing technical support and liaising with the project contractor.  This included providing guidelines on the installation of the; 

  1. GUTEX Wood Fibreboard Insulation.
  2. Thermo Hemp Natural Insulation.
  3. pro clima airtight/windtight systems and associated tapes/seals.

Specification Details

Timber frame walls

Thermo Hemp (140mm) was used on the inside of Timber frame walls with an OSB board and GUTEX Multitherm (60mm) on the outside.  Outside of this was a ventilated layer and cladding.  GUTEX Multitherm allows vapour diffusion, regulates humidity and in addition significantly improves soundproofing.  The uniform board dimensions ensures a speedy installation.

U-Value Result achieved = 0.2 W/mK

Masonry walls

A 100mm internal block was wet plastered for airtightness with sand and cement.  GUTEX Multitherm (160mm) was fixed back to the masonry with helifix wall ties.  pro clima SOLITEX FRONTA HUMIDA was placed in front of the GUTEX Multitherm.  SOLITEX FRONTA HUMIDA protects the GUTEX during the exposed stage, and over the lifetime of the building preventing vapour within the cavity passing through the GUTEX board – providing additional protection. 

U-Value Result achieved = 0.21 W/mK

This project highlighted the adaptability of the GUTEX Multitherm board as it was used both on the outside of a timber frame and on the outside of a masonry wall

Roof Build Up’s

Roof Specification of 1 – Curved roof 2 – Pitched roof


Zinc was used on the outside – beneath this was pro clima SOLITEX UM membrane – This is used under the metal roof and helps prevent corrosion of the zinc from the underside.  UM membrane is 8mm thick with a mesh which allows drainage of any vapour or moisture that may collect between the zinc and the support layer (OSB / PLY). Solitex UM membrane also provides acoustic protection as it acts as an acoustic cushion between the zinc and the ply/OSB layer below…helping reduce impact sound transmission. 

Between the rafters, DAMMSTATT Cellulose Insulation (225mm) was pumped in dry.  pro clima INTELLO PLUS (intelligent vapour control and airtight layer on the inside) followed by a service zone of 60mm Thermo Hemp and plasterboard.

U-Value Result achieved on the Curved Roof = 0.16 W/mK


Again Zinc was used on the outside, followed by a vented cavity and Solitex Plus.  GUTEX Ultratherm (60mm) was used below the Solitex on the outside of the pitched roof, 220mm of Thermo Hemp between rafters and INTELLO PLUS on the inside with a service zone and plasterboard.  Intello Plus features the world's best and most effective variable diffusion resistance, ensuring optimum protection for all fibrous insulating materials in all constructions.

U-Value Result achieved on the Pitched Roof = 0.15 W/mK

GUTEX was used on the outside of the pitched roof in combination with the Thermo Hemp, this ensured an excellent u value was achieved.  The GUTEX and Thermo Hemp combination was a very thermally efficient build up and also ensured the structure was very breathable to the outside.  There were concerns about sound transmission with the zinc on the outside of the roof, GUTEX high-density board and its fibrous natural gives it outstanding acoustic properties.   

In addition, the roof was also going to be inhabited.  GUTEX Ultratherm has an exceptionally effective thermal diffusivity so it absorbs heat during the summer on the metal roof preventing it getting into quick and leading to a comfortable temperature in the summer as well as insulating effectively during the winter months.

GUTEX Ultratherm and Thermo Hemp are very compatible because they are both very breathable materials.

In the content of the walls (Timber frame walls/masonry wall), by using GUTEX Multitherm on the outside of the timber frame this allowed the wall to breathe to the vented cavity. Rather than using the OSB board on the outside, it was used on the inside in conjunction with pro clima tapes and seals.   This acts a Vapour control and airtightness layer, if this was applied on the outside it would not allow Vapour to migrate to the outside as easily, GUTEX on the outside is much more breathable compared to an OSB board. 

GUTEX On the outside of the timber frame allowed more thermal continuity and therefore less thermal bridging.  Likewise, on the masonry wall, GUTEX provided more thermal continuity, especially around window and door thresholds.   

This family home overlooking Lough Melvin has delivered a truly stunning result.  The combination of natural insulation products and pro clima airtightness products will ensure a comfortable, healthy environment all year round.