Orange County

Structural plans for your home addition

Add a room or a second story with foundation and framing plans that connect the new space to your home.

California-licensed Professional Engineers

Home addition framing integrated with an existing Orange County residence

Service scope

What the addition design covers

The design must work for both the new space and the affected parts of the home.

  • Existing framing and foundations where the addition connects
  • New foundation, floor, wall, beam, header, and roof framing
  • Connections and transitions between existing and new construction
  • Gravity and seismic forces from the roof down to the foundation
Exposed residential framing where new space connects to an existing home
The addition and the affected parts of the existing home must be considered as one structural system.
Project team coordinating residential addition plans around a table
Coordinated calculations, plans, and details give the design and construction teams a common reference.

Project deliverables

Deliverables matched to your project

We identify missing survey, soils, or field information before relying on it.

  • Structural calculations based on the confirmed design inputs
  • Foundation, floor, wall, and roof framing plans as applicable
  • Beam, post, shear, holdown, and connection details as required
  • Verification notes, plan-review responses, and construction clarifications when included
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A clear path forward

Plan the tie-in before breaking ground

  1. 01Step
    Step 01

    Share the addition concept

    Send plans, surveys, photos, available records, and the space you want to add.

  2. 02Step
    Step 02

    Design old and new together

    We develop the foundation, framing, and connections around the agreed layout.

  3. 03Step
    Step 03

    Use the completed documents

    Take the agreed package into agency review, contractor pricing, and construction.

Field professional measuring the exterior of an existing home before an addition
Plans, site information, and field verification establish how the new space can connect to the house.
Resolve where the addition meets the house

The biggest structural questions often occur at the transition between old and new.

  • Review of the capacity and condition of affected existing elements
  • Clear roof, floor, wall, and foundation transitions
  • Structural options that protect the intended layout
  • Early identification of needed soils, survey, or field information

What clients say

“Their quality of work and customer service is excellent.”
Maria A. • Irvine, CA
“They were very responsive, helped me salvage what I could from the previous firm, and provided the expertise and knowledge needed to finish the job quickly and efficiently.”
Lisa H. • Laguna Niguel, CA
Homeowners discussing their property with a field professional
A clear project conversation helps align the desired space with the information needed to begin.

Frequently asked questions

What information is needed to engineer an addition?+

Existing and proposed plans, a site plan or survey when available, photos, known foundation information, and the architectural goals are useful starting inputs. Additional field verification may be needed.

Can the existing foundation support a second story?+

That requires evaluation of the current foundation, framing, material assumptions, and proposed loads. The result may be reuse, strengthening, new supports, or a revised design strategy.

Do additions require soils information?+

Requirements vary with site, foundation type, addition size, and jurisdiction. We identify the geotechnical information needed for the structural design.

Do you coordinate with architects and contractors?+

Yes. Coordination helps align structural depth, openings, roof geometry, constructability, and the permit set.

What happens if existing construction differs from the plans?+

We review documented field conditions and determine whether the design needs clarification or revision. Additional work is confirmed before proceeding.

Do I need architectural plans before structural engineering?+

A concept can be enough for early structural input, but full structural documents usually rely on a coordinated architectural layout, dimensions, openings, elevations, and site information. We can identify which inputs are still needed.

Show us the space you want to add

Tell us what you’re considering. We’ll follow up to discuss your project and the next steps.

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