This is a tricky topic since it can vary quite a bit based on project type, quality of construction, quality of materials, time of year, location, and other factors. For that reason, I will give you a few formulas below based on the types of residential projects that Josh PS ordinarily designs in the Seattle area to help you get a rough estimate of your project. We focus on offering a high level of detail and responsive, friendly service, so we are not typically the cheapest architecture firm you may encounter. We do, however, offer a great value for the high quality design services we deliver for the most important investment you will likely ever make. (Also note the federal government considers architectural services to be a professional service similar to legal and medical services, and the price to perform such services can vary quite significantly depending on a multitude of factors that vary in each case. Federal courts have deemed it unlawful to set fixed prices on architectural services, and the architectural registration board establishes strict standards for the professionalism, ethics, and technical knowledge required to be exercised by a licensed architect.) Ok, here it goes...I dare to try to explain how this all works without getting too complicated:
NEW CONSTRUCTION: New construction is actually cheaper than remodeling in many circumstances. Lets assume you are doing average quality of construction with basic materials. The construction cost for low quality construction tends to be about $200 per square foot which might get you a basic garage. For average quality, $300 per square foot is a better budget number. Bathrooms and kitchens (with tile, countertops, appliances, fixtures, cabinets, etc) easily cost over $400 per square foot, and bedrooms and living rooms are closer to the lower end number of $200 per square foot since they are usually just drywall and carpet without any expensive finishes. This is how a basic level of construction averages out to around $300 -$350 per square foot. Enhancing the quality of construction or quality of materials to nicer finishes will easily bring a construction cost to over $400 per square foot or more. If you'd like a project like you tend to see in magazines, plan for $500 per square foot or more. We have worked on high-end projects that are over $1000 per square foot. Design fees for new construction are also a little cheaper than design fees for renovations. This is because we do not need to measure, analyse, and coordinate new construction with existing construction. It is usually possible for us to provide full design services for around 10% of the construction cost. This includes designing the preliminary concept, drawing and coordinating the permit process, and producing construction drawings to get the builder started with the bidding and construction process. If the client and building department minimize design changes, we can usually also complete the construction administration (coordination of design detailing during construction) within that 10% fee. Almost all architects bill hourly since it is never possible to guess at the exact amount of time needed to spend on each project, so this 10% figure is just a guide since complexities of different projects can vary. New construction on a waterfront or steep slope (or both) can be much more difficult to design and build, or a simple box-shaped building with a flat roof can be much more simple than one with multiple building wings and roof lines. Also, smaller projects tend to cost more to design and build than larger projects since the legwork is similar for both: they both use the same permit forms/procedures, they both require the same number of meetings, specifying construction materials takes the same amount of time for a small room as it does for a large room, and a $20,000 construction cost for a water connection is the same on a small and larger project. This causes design fees for smaller projects to be a higher proportion like 15% of the construction cost.
To give you an example of a new construction estimate, consider a basic quality home, with simple materials, on a flat site could cost around $350 per square foot to build. If it is 2000 sq feet, that would be a $700,000 construction cost. A design fee at 10% of that would be $70,000. Other costs to be aware of would be structural engineering which would normally be around $4000 and up, geotechnical engineering if the soil conditions are poor at around $3000 and up, a surveyor at $2000 and up, the cost of the permit which is around $5000 and up, and the cost of the land (to name the most common fees). Also, the construction cost quoted from the builder usually does not include their 15% overhead/profit, insurance, and sales tax which is another 10% in the Seattle area.
ADDITIONS TO THE GROUND FLOOR: Ground floor (single and double floor) additions are handled very similar to the new construction commentary above if the construction is all new, and there are minimal changes to the existing building. Every addition is different in terms of how it affects the structure of the existing building, but the parts of the project that are considered "new" can be estimated according to the formula above. The portions of the project that require demolition, retrofitting, or attachment to the existing structure can be estimated according to the commentary below on renovations. For design fees, the 10% of construction cost fee described above is also applicable for the new portions of an addition project, but the architect is also required to measure, draw, analyse, and coordinate all aspects of the existing building. This takes additional time beyond the new construction formula above, and it varies based on the size and complexity of the existing structure. We can usually measure and draw an average sized existing building for around $2500 and up, and this becomes the "blank canvas" for designing and drawing the changes to the existing structure as well as the addition to it. Also, most additions are not simply "just additions." There's ordinarily some renovations of the existing structure necessary for the addition to function properly. These unknowns make estimating costs of renovated areas very difficult. Again, refer to the formula below for renovations to estimate the costs of the renovated portions separately from the newly added portions.
To give you an example of an estimate for an addition, lets consider adding a basic quality 200 square foot, single-floor addition of a family room (without a basement) to an existing residence. The addition would cost around $350 per square foot for basic quality (or more for higher-end quality). This would be $70,000 to build the addition plus the additional cost of retrofitting the portion of the existing house that connects to it. If 100 square feet of space within the existing residence needs tore apart, updated, and put back together, that could cost $300 per square foot for that portion of the work (which is another $30,000). That totals $100,000 in construction cost. Also, the construction cost quoted from the builder usually does not include their 15% overhead/profit, insurance, and sales tax which is another 10% in the Seattle area. Design fees at around 10% (give or take) would be $10,000 plus another $2500 to measure, draw, analyse the whole house. Engineering, permits, and surveys are additional costs as explained above, Also consider unexpected costs for upgrading a heating system. If you are adding more space, can your existing furnace keep up with it?
UPPER FLOOR ADDITIONS: These are among the most tricky projects to design and build because they rely upon being supported by the integrity of the existing building below (and thorough documentation of all of it). In almost every case, the existing building is not currently built to support the weight of additional floors, walls, and roofs above. By removing an existing roof to make way for new floors, walls, and roofs, the builder must significantly disrupt the existing building from the ground up. The existing foundations often need to be upgraded to carry the additional weight of the new addition above. Also, the existing walls on the first floor need to be upgraded as well. While doing this work, ceilings and walls are often damaged or demolished to enable access to plumbing, electrical, and duct work. When an exterior wall is torn apart, it is also required to be insulated to the current energy code standards (which often requires the wall to become thicker to accommodate the mandated amount of insulation). Most homes were built before the current requirements of the building codes, so the engineer needs to figure out ways to brace the building from side-to-side motion (lateral forces) such as wind and earthquakes. This usually entails adding plywood to the interior or exterior side of existing walls (which requires removal of siding or drywall). This also requires attaching the wood components of the walls and floor to the concrete foundations. Believe it or not, most older homes are not attached to their foundations - they are simply resting there. A simple side-to-side movement of a couple inches could cause the entire house to fall off the foundation causing a total loss. Adding an upper floor makes the house top-heavy which compounds this issue. People new to upper floor additions usually only consider adding stronger beams to accommodate the extra weight above that pushes down on the existing structure due to gravity, and they are unaware of the implications of lateral force upgrades which often affects areas of the existing house nowhere near the proposed upper floor addition. This commentary illustrates the complexity of adding an upper floor, and the ramifications it has on the rest of the building. For that reason, upper floor additions should be estimated at $350 per square foot and up for the addition portion, and another $200 per square foot for the areas below (and around) the addition that will need taken apart, protected, retrofitted, and rebuilt. The architect will also need to measure, draw, and analyse the entire existing home which is usually $2500 or more depending on the size and complexity of the building, The architect will also need to design, permit, and coordinate the affected areas around the addition. Because of the additional coordination, design fees can exceed 10% of the construction cost and approach 15%. All of the unknowns with removing a roof and supporting an additional floor on unknown existing conditions makes estimating upper floor additions very difficult.
To give you an example of estimating an upper floor addition, lets propose adding a basic 200 square foot, upper floor, bedroom addition over an existing single-floor residence with a finished basement, The added portion would cost around $70,000 (at $350 per square foot) plus any costs of rebuilding the first floor and basement below which could easily add an additional $60,000 if those areas cost $300 per square foot to deconstruct, upgrade, and rebuild. Also, the construction cost quoted from the builder usually does not include their 15% overhead/profit, insurance, and sales tax which is another 10% in the Seattle area. At a construction cost of $130,000, the design fees could be $13,000 and up to $19,500. It also takes about $2500 and up to measure and draw the existing building. High-end and more complex projects could cost even more to design and build. Engineering, permits, and surveys are additional costs as explained above. Also consider unexpected costs for upgrading a heating system. If you are adding more space, can your existing furnace keep up with it?
INTERIOR RENOVATIONS (REMODELS): These projects do not add any new space to the home, but they refinish existing space which makes them a little more complicated than a new construction project. To refinish existing space, the builder needs to remove walls and/or finishes to access the structure, plumbing, electrical, and duct work. As they do this, they need to be careful to protect other parts of the house that are not affected by the work. This causes the pace of work to be slower, and retrofitting new finishes into existing ones is also a bit more difficult. Occasionally, interior renovations can affect other areas of a home outside of the area of the project if it is necessary to update plumbing or electrical, for example. For these reasons, it is advisable to estimate basic interior remodels of non-kitchens and bathrooms at $400 per square foot. Kitchens and bathrooms are going to be a bit more since they involve more expensive materials and labor to install tile, counters, cabinets, appliances, fixtures, etc. Design fees also tend to be 10% and up to 15% of the construction cost due to the extra coordination necessary with other parts of the existing building before we can begin designing the proposed changes. Integrating proposed changes within existing conditions is a bit more challenging than working with a blank canvas. It also usually takes us around $2500 or more to measure and draw the existing house depending on the size and complexity of it.
To give you an example of estimating an interior renovation project, let's consider a simple 200 square foot living room remodel within an existing house. It would cost around $2500 to measure and and draw the existing residence (assuming it is even necessary at all for this scenario). The construction cost would likely be around $80,000 if the construction cost is $400 per square foot. It could certainly cost less if the renovations minimally impact the existing conditions. Also, the construction cost quoted from the builder usually does not include their 15% overhead/profit, insurance, and sales tax which is another 10% in the Seattle area. Design fees for the remodeled portions would be around $8000 to $12,000. Additional costs could include permits and engineering if load-bearing walls are being removed.