EWI to Existing Conservatory

Author details

Original Author:Admin Organisation:Retrofit Pattern Book

Detail summary

Detail for External Wall insulation fitted around the junction of an existing conservatory and an existing wall. Designed to help preserve an existing conservatory construction whilst installing EWI in order to mitigate heat loss through the building envelope.

Technical description

Plan detail. EWI to existing conservatory. Junction with external wall.

Reference Specification:

Expanded polystyrene (EPS): To BS EN 13163. Installed by system manufacturer/ contractor approved by manufacturer to weather-tight installation, to resist dead and live loads inc. impact and wind loads. Do not install in adverse weather conditions.

Installation: by system manufacturer, or a contractor approved by the system manufacturer.

  • Weathertight under all anticipated conditions.
  • Capable of resisting all dead loads and design live loads, including impact and wind loads, and accommodating all thermal movements without damage.


Materials/ Surfaces: Do not use frozen materials and do not apply materials to frost bound surfaces.

British Standards- please ensure:

  • Sloping and vertical patent glazing: to BS 5516-1.
  • Access and openings: In accordance with BS 8213-1
  • Insulating glass units to BS 5713 and Kitemark certified or to BS EN 1279.
  • Perimeter seals: Resistant to UV light degradation on exposed edges. Edge seal strength: To BS EN 1279-4.
  • Timber windows to BS 644, With Timber members for purpose made windows to BS EN 942.
  • Where safety glazing used in door leaves, standard to BS 6262-4 and to BS 6206 for safety plastics and BS EN 12600 for safety glass.

Installation of fire resisting and/ or smoke control doors/doorsets: In accordance with instructions supplied with the product conformity certificate, test report or engineering assessment.

Gaps between frames and supporting construction: filled as necessary in accordance with requirements for certification and/or door/ doorset manufacturer's instructions.

For fire door lining and escape route guidence, refer to: Approved document B (fire safety) for guidance for both dwellings and non-dwellings for existing buildings.

Approved Document F (ventilation) should be referred to with regards to ventilation as part of window or door construction.

Documents K (protection from falling) and doc M (Access) should also be referred to when installing external patio doors.

Care should be taken during the installation to ensure the continuity of insulation and air-tightness at the junction between window, existing wall and external wall insulation.

Parts list

  • Recycled plastic Block [FAB EW06b]

    Recycled plastic lumber @ 900c/c.

    • Thickness: As detail.
    • Depth: as detail.
    • Width: as glazing frame.

    British Plastics. Tel: 01422 88 57 61 Web: http://www.britishrecycledplastic.co.uk/
    Product Reference: Recycled plastic lumber

  • Foam EWI System (140mm), rendered finish [FAB EW02]

    Vapour permeable expanded polystyrene (EPS) external wall insulation: To BS EN 13163.

    • Thermal conductivity: 0.031W/m2K.
    • GWP: <5.
    • Fixing: Adhesive bedding and mechanical fixing to substrate in accordance with manufacturer's recommendations.
    • Adhesive layer: Baumit openContact - round perimeter of each board and three dabs within on each board.
    • Fixing anchor: Baumit STR U.
    • Basecoat: Baumit openContact.
    • Reinforcement : Baumit openTex.
    • Primer: Baumit openPrimer.
    • Topcoat: Baumit Nanopor Top.
    • Beads/ Trims: Manufacturer's standard.
    • Finish Colour: See schematic.
    • System Guarantee: 25 years - ECO Compliant insurances and guarantees.
    • System Certification: ETAG.

    Baumit: Tel: +44 (0) 333-358 3434
    Fax: +44 (0) 843-557 7666
    Web: http://www.baumitinsulation.co.uk
    Product Reference: Baumit EWI system open.
    Insulation: Baumit open reflect - vapour permeable EPS.

  • Woodfibre EWI accesssories [EW02]

    Corner bead for render reinforcement at external corners

    As EWI manufacturers/suppliers.


  1. Admin - 2015-04-28 17:11:24 [Displayed version]

    Version 1. New detail uploaded

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