Additions

Process Overview, Additions:  Expand footprint with new foundation and tie-in to existing home structurally and aesthetically.  

When is this a good idea?  Additions make sense when the footprint is too small and there is extra lot space available.  Additions often involve a second story and basement.  

What's Involved Preliminary:

• Soil sample and soil report [6 weeks]
• Boundary survey [2-3 weeks]
• Architectural layout design, site plan, and bulk plane drawings including revisions [4-5 weeks]
• Structural engineering design & report [3-5 weeks]
• Estimate from general contractor (GC) [2-4 weeks]
• Estimate contract revisions & approval [2 weeks] 
• Plan review and approval from Landmark (if building is located within designated historic district) [2 weeks]
• Permit--includes initial plan review submittal, resubmittals and processing approval time with building department [6-10 weeks]
• Neighbor notification letters [1-4 weeks]
• Total Preliminary timeline [3-4 months]  (some steps occur simultaneously) 

What's Involved Construction:

• Temporary fencing [1 day]
• Excavation [1-2 days]
• Foundation & footings forms, rebar, inspections, concrete pour [2-3 weeks]
• Foundation damp proofing [1 day]
• Underground plumbing including inspections (if adding basement space) [1 week]
• Prep and pour basement slab (if adding basement space) [1 week]
• Install egress window well walls (if adding basement space) [1 day]
• Exterior perimeter drain to sump pit & inspection [1 week]
• Backfill dirt [1-2 days]
• Demo prep including dust containment, floor protection, and work zone set up [1 week]
• Install beams and posts per structural engineering report (including temp walls and post footings) [1 week]
• Demo house walls/roof. Tarp for temp roof. [2 weeks]
• Frame walls and roof. Dry in roof with underlayment [3 weeks]
• Electrical, plumbing, HVAC rough-in installations including inspections [5 weeks]
• Siding, windows, exterior doors, roof, gutters & downspouts including inspections [4-6 weeks]
• Insulation and drywall including inspections [3-4 weeks]
• Finishes including trim, painting, tiling, flooring, bathrooms, kitchen [6-8 weeks]
• Total Construction timeline ~ [6 months]

Typical cost:  400 SF x 2 levels ~ $200k and up. Nearly all additions involve renovating other parts of the home. Therefore, costs will vary dramatically with kitchens and bathrooms being the biggest expenses. 

Accessory Dwellings Units (ADU's)

A second residence on the property of a single-family house, or second residence within a single-family house (such as an apartment over the garage or a smaller house in the backyard) with its own separate entrance and living space.

What’s the difference between an ADU and a duplex? A duplex is made up of two joined, but separate properties that may have separate owners. An ADU, on the other hand, is “accessory” to the primary unit on the property.

Process Overview, ADU's:  Typical ADU projects in Denver are new garages with a studio apartment above. 

When is this a good idea?  ADU's make sense as means of earning a passive income or an adult family member needs to be nearby with a little privacy.  

What's Involved Preliminary:

• Soil sample and soil report [6 weeks]
• Boundary survey [2-3 weeks]
• Architectural layout design, site plan, and bulk plane drawings including revisions [2-3 weeks]
• Structural engineering design & report [2-4 weeks]
• Estimate from general contractor (GC) [2 weeks]
• Estimate contract revisions & approval [2 weeks] 
• Plan review and approval from Landmark (if building is located within designated historic district) [2 weeks]
• Permit--includes initial plan review submittal, resubmittals and processing approval time with building department [3-5 weeks]
• Neighbor notification letters [1-4 weeks]
• Total Preliminary timeline [2-3 months]  (some steps occur simultaneously) 

What's Involved Construction:

• Temporary fencing [1 day]
• Excavation [1-2 days]
• Foundation & footings forms, rebar, inspections, concrete pour [2-3 weeks]
• Underground plumbing including inspections[1 week]
• Prep and pour garage slab [1 week]
• Backfill dirt & grading [1-2 days]
• Frame walls, floors and roof. Dry in roof with underlayment [2 weeks]
• Electrical, plumbing, HVAC rough-in installations including inspections [3 weeks]
• Siding, windows, exterior doors, roof, gutters & downspouts including inspections [3-4 weeks]
• Insulation and drywall including inspections [3-4 weeks]
• Finishes including trim, painting, tiling, flooring, bathrooms, kitchen [4-6 weeks]
• Total Construction timeline ~ [3-5 months]

Typical cost:  600 SF 3 car garage with 600 SF studio apartment ~ $175k and up. 

To determine if your Denver property is zoned to allow ADU's check the zoning map & zoning descriptions.

ADU Considerations:

Forestry Review:  Required if project will impact the canopy or roots of street trees.

Tap Fees:  Building an accessory dwelling requires water and sewer tap fees and they are substantial:  Denver 2017 sewer tap fees & Denver Water tap fees

Pop-Tops

Process overview pop tops:  tear off existing roof and build second story on top of existing foundation walls.

When is this a good idea?  Pop tops make sense when your basement is already finished and you need more square feet, Plus, today's main level open floor plans push the master suite to the second level and/or basement.

What's involved:

• Soil sample and soil report [6 weeks]
• Boundary survey [2-3 weeks]
• Architectural layout design, site plan, and bulk plane drawings including revisions [4-5 weeks]
• Structural engineering design & report [3-5 weeks]
• Estimate from general contractor (GC) [2-4 weeks]
• Estimate contract revisions & approval [2 weeks] 
• Plan review and approval from Landmark (if building is located within designated historic district) [2 weeks]
• Permit--includes initial plan review submittal, resubmittals and processing approval time with building department [6-10 weeks]
• Neighbor notification letters [1-4 weeks]
• Total Preliminary timeline [3-4 months]  (some steps occur simultaneously) 

What's Involved Construction:

• Dust containment, floor protection, temporary fencing and work zone set up [1 week]
• Demo of existing roof, walls & ceilings. Tarp for temp roof. [2 weeks]
• Install beams and posts per structural engineering report (including temp walls and post footings) [1 week]
• Frame 2nd story & roof. Dry in roof with underlayment [3 weeks]
• Electrical, plumbing, HVAC rough-in installations including inspections [5 weeks]
• Siding, windows, exterior doors, roof, gutters & downspouts including inspections [4-6 weeks]
• Insulation and drywall including inspections [3-4 weeks]
• Finishes including trim, painting, tiling, flooring, bathrooms, kitchen [6-8 weeks]
• Total Construction timeline ~ [6 months]

Overall Total timeline ~ 9 months

Typical cost:  1000 SF 2nd story ~ $225k and up. Nearly all pop tops include renovating the main floor, therefore, the cost can vary dramatically. Kitchens and bathrooms are the biggest cost drivers.