Energy Performance, Envelope and HVAC

Factory production can support careful air sealing and insulation, but module joints, site connections and destination climate remain critical.

Reviewed for destination-code contextInternational with U.S. and Canadian emphasis
Permanent-home context: This guide uses “modular home” for a code-compliant building made as three-dimensional modules, transported to a permanent site and assembled on an approved foundation. It does not use the term as a synonym for a trailer, mobile home or HUD-code manufactured home.

Set a destination target

Energy-code requirements and climate data vary. Decide whether the project will meet minimum code or pursue a higher performance target before wall systems and windows are selected.

Request assembly details and calculations that reflect the final destination, not a generic brochure value.

Protect the module envelope

Air, water and thermal control layers must continue across marriage lines, roof joints, foundations and site-built additions. These interfaces deserve drawings and inspection.

Transport can expose modules to wind-driven rain. Ask about wrapping, temporary roofs, moisture checks and acceptance criteria on arrival.

Size systems for the finished house

Heating and cooling equipment should be based on a load calculation for the completed building. Factory assumptions may need adjustment for orientation, foundation and local design temperatures.

Commission ventilation, controls and cross-module duct or refrigerant connections before occupancy.

Apply this guide to a real project

For energy performance, envelope and hvac, create a dated project note tied to the destination address and current drawing revision. Identify the authority, designer, factory or contractor responsible for each unresolved item. Attach the written evidence for ‘What destination energy code and performance target apply?’ and ‘How do control layers cross module and foundation joints?’ rather than recording a verbal assurance.

Before a deposit, production release, shipment or final payment, convert every open question into a named action with an owner and deadline. Keep superseded drawings and decisions in the record so later inspectors, lenders, insurers and future owners can understand why the completed house differs from an early sales plan.

Questions to resolve before proceeding

  • What destination energy code and performance target apply?
  • How do control layers cross module and foundation joints?
  • What moisture inspection occurs after transport?
  • Who completes HVAC load calculations and commissioning?
Stop point: Do not accept equipment selected only by floor area or factory model name.