New home built beside 100 year-old farmhouse

For Alan and Karen Campbell renovating a century old farmhouse in Co Derry – and building their very own family home next to it – meant they could care for elderly parents.

This new build, built next to the family farmhouse, was a labour of love for Alan and Karen. Here they chat about:

  • Challenges of designing a new build next to a 100-year-old farmhouse
  • Re-roofing the farmhouse
  • Insulating the farmhouse from inside (drylining with steel stud walls)
  • Delays with CTY10 planning permission for the new build
  • Ridge height restrictions for the new build
  • Tender process and choosing a builder
  • Terms of the contract with the builder
  • Cost engineering to keep the build within budget
  • Hot water system plumbing for renewables
  • External render and cladding tips
  • Landscaping choices
  • Issues with utility connections

New build overview

House size: 1,990 sqft
Plot size: 9 acres
EPC (SAP): B (86)
Costs: Original forecast was £127,000; spent £134,500.
House value estimate: £350,000
Heating and hot water: oil boiler
Ventilation: natural
Walls: cavity walls 100mm blocks filled with 90mm graphite EPS beads, insulated plasterboard with 50mm insulation on inner leaf, U-value 0.15 W.sqmK
Floor: 150mm subfloor, 2x50mm PIR board, 100mm screed, U-value 0.14 W/sqmK
Roofs: pitched roof total 150mm PIR insulation, Spanish natural slate roof covering U-value
0.16 W/sqmK; flat roof 2x 300mm mineral wool U-value 0.14W/sqmK


Written by Astrid Madsen

Astrid Madsen is the editor of the SelfBuild magazine. She previously held the same role in an Irish trade publication, before that she worked at the National Standards Authority of Ireland. She graduated with a BA in Urban Studies from Columbia University in New York and holds an MBA from the Instituto de Estudios Bursatiles in Madrid. France of origin, she now lives in Portarlington, County Laois, where she's taken on the task of renovating a listed building! Email

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