Who this guide is for
- Homeowners specifying interior trim
- Renovators matching casing to a home's style
- Anyone confused by profile and reveal choices
- People planning consistent trim across a home
Casing profile families
Casing ranges from simple, flat, contemporary profiles to detailed, moulded, traditional ones. The profile carries much of the trim's character, so choosing a family that suits the home is the first decision.
- Flat and simple contemporary profiles
- Moulded traditional profiles
- Profiles that suit the home's era
Reveal and proportion
The reveal, how the casing sits relative to the frame, and the trim's proportion affect how considered the result looks. Casing that is too narrow can look mean, while generous trim reads as deliberate. Proportion matters as much as profile.
- Consider the reveal at the frame
- Match trim proportion to the room
- Avoid trim that looks mean or oversized
Mitered versus butt joints
How casing meets at corners, mitered at an angle or butted with a square join, changes the look and suits different profiles. The joint approach is part of the style language, so it is worth deciding alongside the profile.
Consistency across the home
Trim reads well when consistent. Deciding a casing approach for the whole home, rather than room by room, keeps doors and windows feeling like part of one scheme. Coordinating with skirting and other trim reinforces this.
- Decide a casing approach for the whole home
- Coordinate with skirting and other trim
- Keep doors and windows consistent
Casing and trim planning checklist
- 1Identify a profile family that suits the home
- 2Consider the reveal at the frame
- 3Match trim proportion to the room
- 4Decide on mitered or butt joints
- 5Coordinate casing with skirting and trim
- 6Plan a consistent approach across the home
- 7Keep doors and windows feeling unified
- 8Confirm cutting and fixing with a trade
Common mistakes to avoid
- Choosing a profile that fights the home's style
- Using trim too narrow for the room
- Mixing joint approaches inconsistently
- Specifying casing room by room with no overall plan
- Ignoring how casing relates to skirting and other trim
When to involve a professional
- Cutting and fixing should be handled by a qualified trade
- Trim material choices are covered separately
- Requirements and feasibility vary by home and project
- This page makes no brand or product recommendations
Frequently asked questions
Questions readers ask about this topic
What is casing?
Casing is the trim that frames doors and windows. Its profile, from simple and flat to detailed and moulded, quietly sets a room's character and level of formality, which is why choosing a suitable family matters.
What is a reveal?
The reveal is how the casing sits relative to the frame it surrounds. Along with the trim's proportion, it affects how considered the result looks. Casing that is too narrow can look mean, while generous trim reads as deliberate.
Mitered or butt joints, which?
Both are valid. Mitered joints meet at an angle, while butt joints use a square join; each suits different profiles and looks. The joint approach is part of the style language, so decide it alongside the profile.
Should trim be consistent throughout?
Generally, yes. Trim reads well when consistent, so deciding a casing approach for the whole home keeps doors and windows feeling unified. Coordinating with skirting and other trim reinforces that sense of one scheme.
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