Optimum Value Engineering and Integrated Design (OVE/ID) provides concise summaries of framing and design measures that can reduce construction costs and improve energy efficiency. Key measures include framing walls, floors, and roofs on a 600mm modular grid to reduce materials; aligning structural elements to transfer loads directly; and coordinating window and door locations with framing to minimize extra studs. Adopting these OVE/ID principles typically saves a builder $500-1000 per house through lower materials and labor.
2. OVE/ID
Background
● OVE/ID is little more than applied common sense.
● OVE/ID concepts are not new,
in fact they have been
in use by some builders
for three or four decades.
● Fits nicely with the “House As
A System” philosophy
New technology???
T. Eaton Co. mail-order houses
which used 24” o/c spacing for
the wall studs (circa. 1920).
3. Optimum Value Engineering (OVE)
What Is It?
● Can be defined as a construction philosophy in
which components and systems are designed to
meet their intended objectives without excessive
or unnecessary use of resources.
● In practice, most houses (both new and existing)
are over-designed relative to what is required by
the National Building Code – especially from a
structural perspective.
● Thus, money is expended without any
corresponding benefit.
24 members to protect a
plumbing chase??
4. Integrated Design
What Is It?
● Can be defined as a design approach in which all design
requirements are considered simultaneously rather
than sequentially.
● This permits their competing design requirements to be
better balanced.
● Parallels the famous “House As A System” philosophy
used by the R-2000 Standard.
5. OVE/ID
OVE/ID Measures Fall Into Three Categories
a) Framing measures
b) Mechanical system measures
c) Overall design measures
6. OVE/ID
a) Framing Measures
1. Design the house using 600 mm (24”) modules for
the walls, floor and attic framing. Since most board
materials (drywall and sheathing products) are also
based on this dimension, wastage is
automatically reduced.
8. OVE/ID
Framing Measures (con’t)
2. Align the structural loads for the attic, walls and
foundation which permits direct transfer of loads
and allows unnecessary framing materials
to be eliminated.
10. OVE/ID
Framing Measures (con’t)
3. Coordinate wall openings with the basic 600 mm (24”)
dimension thereby reducing the number of studs,
cripples and other components
13. OVE/ID
b) Mechanical system measures
- Aligning mechanical systems to avoid unnecessary runs
- Designing the mechanical system based on need rather
than historical practice
c) Overall design principles
- Optimizing window selection
14. Benefits Of OVE/ID
● Lower construction costs – more intelligent design results in lower costs.
● Reduced wastage of framing materials creates environmental benefits.
● Reduced heat loss – reduced use of framing materials means fewer
thermal bridges.
15. Disadvantages Of OVE/ID
● More careful design practices are required
(more thought).
● Better site supervision is required – at least initially.
● Potentially negative homeowner perception – “less
wood means cheaper construction??” – NO!
OVE means “more insulation” not “less
wood”.
16. OVE/ID Measures
a) Framing Measures
1. Exterior wall framing at 600 mm (24”) o/c
2. Floor framing at 600 mm (24”) o/c
3. OVE framing
4. Optimum joist length and beam location
5. Elimination of floor system cross-bracing
6. Support of non-load bearing partition walls
7. Drywall clips at corners
8. Non-Load Bearing partition walls
9. Coordinated framing for windows and doors
10. Elimination of lintels in non-load bearing walls
17. OVE/ID Measures
b) Mechanical System Measures
11. Simplified plumbing stack venting
12. Core distribution for forced air heating systems
c) Overall Design Principles
13. Optimized window selection
18. 1. Exterior Wall Framing At 600 mm (24”) o/c
Background
● The vast majority of Canadian houses use 400 mm (16”) o/c
stud spacing for exterior wall construction.
● This exceeds the NBC requirements – 400 mm spacing is
only needed structurally required when the wall is
supporting two or more floors.
● Why? (“Cuz that’s how we’ve always done it.”).
.
19. 1. Exterior Wall Framing At 600 mm (24”) o/c
OVE/ID Alternative
● Use 600 mm (24”) o/c spacing unless narrower spacing
is structurally required.
● Use wider insulation batts to fit the wider wall cavities.
20. 1. Exterior Wall Framing At 600 mm (24”) o/c
Advantages (to the builder)
● Reduced labour and material costs (eliminates 1/3 of
all wall studs).
Advantages (to the homeowner)
● Reduced thermal bridging meaning fewer building
envelope problems.
● Energy saving: average of 225 kWhe/yr
(worth $11 to $22 per year).
21. 1. Exterior Wall Framing At 600 mm (24”) o/c
Cost Savings
● Typical new house: $270, assuming 13 mm (1/2”) drywall is used.
● If 16 mm (5/8”) drywall is used to reduce deflection, then
savings are reduced to about $44 per house.
● Material savings, per floor (imperial units)
= (0.25) x (wall perimeter, ft) x (stud cost)
- [(0.031) x (wall area) x (insulation cost / ft2)
Material savings, per floor (metric units)
= (0.82) x (wall perimeter, m) x (stud cost)
- [(0.031) x (wall area) x (insulation cost / m2)]
● Labour savings = 1.2 x (material savings)
22. 2. Floor Framing At 600 mm (24”) o/c
Background
● Structural requirements for floors are largely dictated by
the need to control vibration, improperly designed
floors tend to be springy.
● However, some builders automatically use 400 mm (16”) o/c
spacing when 600 mm (24”) would meet code requirements.
● Structural requirements for dimensioned wood floor systems
are defined in the “Span Tables” of the NBC.
● If an engineered floor system is used (wood I-joists, wood or
metal web systems, etc.), then design to the manufacturer’s
23. 2. Floor Framing At 600 mm (24”) o/c
OVE/ID Alternative
● Frame dimensioned wood floor systems with the floor
joists spaced 600 mm (24”) o/c, if permitted by the
NBC Span Tables.
● Generally not applicable to house which use engineered
floor systems.
● May require a thicker sub-floor, which reduces the
savings by about 25%.
24. 2. Floor Framing At 600 mm (24”) o/c
Advantages (to the builder)
● Reduced labour and material costs.
Advantages (to the homeowner)
● Energy saving: none.
25. 2. Floor Framing At 600 mm (24”) o/c
Cost Savings
● Typical new house: $450, if sub-floor thickness is unchanged.
$320, if thicker sub-floor is required.
Case 1 – Sub-floor thickness unchanged
● Material savings (imperial units)
= (0.25) x (floor area, ft2) x (joist cost per foot)
Material savings (metric units)
= (0.82) x (floor area, m2) x (joist cost per metre)
● Labour savings = (0.47) x (material savings)
Case 2 – Sub-floor thickness increased
● Material savings (imperial units)
= (0.25) x (floor area, ft2) x (joist cost per foot) – (0.094) x (floor area, ft2)
Material savings (metric units)
= (0.82) x (floor area, m2) x (joist cost per metre) – (floor area, m2)
● Labour savings = (0.72) x (material savings)
26. 3. OVE Framing
Background
● This ties measures 1. and 2. together with roof trusses
spaced 600 mm (24”) o/c to permit direct load transfer.
● This allows the second top
plate to be eliminated but
requires metal connectors
to tie in the partition walls.
● Major issue is the availability
of pre-cut 2.39 m
(94 1/8”) wall studs.
27. 3. OVE Framing
OVE/ID Alternative
● Align the roof trusses, wall studs and floor joists to
permit direct transfer of roof loads.
● Eliminate second top plate from exterior walls and
interior partitions and tie two wall systems together
with metal connectors.
● May not be applicable to houses with complicated
floor plans or geometry.
28. 3. OVE Framing
Advantages (to the builder)
● Reduced labour and material costs.
Advantages (to the homeowner)
● None.
● Energy saving: average of 100 kWhe/yr
(worth $5 to $10 per year).
29. 3. OVE Framing
Cost Savings
● Typical new house: $100, assuming that 2.39 m (94 1/8”) studs
are available with the extra length costing the same per unit length
as the studs.
● Material savings, per floor (imperial units)
= [(0.94) x (stud cost per foot) + 0.14] x (wall perimeter, feet)
Material savings, per floor (metric units)
= [(0.29) x (stud cost per metre) + 1.33] x (wall perimeter, metres)
● Labour savings = 0.5 x (material savings)
30. 4. Optimum Joist Length
And Beam Location
Background
● When dimensioned lumber is used for the floor, off-centre joist splices can
be used to maximize the use of even-length members & eliminate overlaps.
● Alternatively, if joist lengths on each side of the beam have the same length,
the beam can be offset slightly so the butt joints are located over the beam.
31. 4. Optimum Joist Length
And Beam Location
OVE/ID Alternative
● Applicable to house which use dimensioned lumber
floor systems.
● Use splices in the floor joists to reduce wastage.
● Alternatively, use floor joists of the same length on each
side of the beam and offset the beam so the joist butt
joints can be positioned over the beam.
32. 4. Optimum Joist Length
And Beam Location
Advantages (to the builder)
● Reduced labour and material costs.
Advantages (to the homeowner)
● None.
● Energy saving: none.
33. 4. Optimum Joist Length
And Beam Location
Cost Savings
● Typical new house: $50, assuming an average of 0.6 m (2’) of
joist length can be saved for each joist spanning from wall to
wall.
● Material savings, per floor (imperial units)
= [(floor area, ft2) / (28) + 2] x (joist cost per foot)
Material savings, per floor (metric units)
= [[(floor area, m2) / (8.54) + 2] x (joist cost per metre)
● Labour savings = 0
34. 5. Elimination Of Floor Cross-Bridging
Background
● 38 x38 (2x2) cross-bridging is used on many dimensioned floor systems
In many instances, the cross-bridging can be eliminated if furring strips
(19x19, 1x4) are nailed to the undersides of the joists.
● Alternatively, a panel-type ceiling can be used underneath
the joists.
35. 5. Elimination Of Floor Cross-Bridging
OVE/ID Alternative
● Applicable to houses dimensioned lumber
floor systems.
Advantages (to the builder)
● Reduced labour and material costs.
Advantages (to the homeowner)
● None.
● Energy saving: none.
36. 5. Elimination Of Floor Cross-Bridging
Cost Savings
● Typical new house: $110.
● Material savings, per floor (imperial units)
= [(floor area, ft2) / (5.1)] x (cross-bridging cost per foot)
Material savings, per floor (metric units)
= [(floor area, m2) / (1.6)] x (cross-bridging cost per metre)
● Labour savings = 1.9 x (material savings)
37. 6. Support Of Non-Load Bearing
Partition Walls
Background
● Partition walls which are not load-bearing and run parallel
to the floor joists do not require a double floor joist
underneath them.
● The National Building Code of Canada permits wood
blocking to be used (typically 38x89 (2x4) members)
spaced 1.2 m (4’) underneath the partition wall
.
38. 6. Support Of Non-Load Bearing
Partition Walls
OVE/ID Alternative
● Use wood blocking, such as 38x89 (2x4) members at 1.2 m (4’) o/c, under
non-load bearing partition walls instead of doubled floor joists.
39. 6. Support Of Non-Load Bearing
Partition Walls
Advantages (to the builder)
● Reduced labour and material costs.
Advantages (to the homeowner)
● None.
● Energy saving: none.
40. 6. Support Of Non-Load Bearing
Partition Walls
Cost Savings
● Typical new house: $240, with the greatest savings occurring
with larger houses.
● Material savings, per floor (imperial units)
= (0.8) x (wall perimeter, ft) x (joist cost per foot)
Material savings, per floor (metric units)
=(0.8) x (wall perimeter, m) x (joist cost per metre)
● Labour savings = 0.7 x (material savings)
41. 7. Drywall Corner Clips
Background
● Three-stud corners are the norm in wood
wood frame construction with two studs
structurally supporting the ends of the
walls and the third providing backing
for one edge of the drywall.
● Structurally, the third stud can be
eliminated and replaced with drywall
clips.
42. 7. Drywall Corner Clips
OVE/ID Alternative
● Eliminate third stud at corners and use three drywall clips
to support the end of the intersecting sheet of drywall.
● Only applies to inside corners. Can also be used for other
applications such as intersecting partition walls and to
minimize problems with truss uplift.
● Also, very useful for retrofit applications.
43. 7. Drywall Corner Clips
Advantages (to the builder)
● Reduced wood usage.
Advantages (to the homeowner)
● Reduced thermal bridging meaning fewer building
envelope problems.
● Energy saving: average of 100 kWhe/yr
(worth $5 to $10 per year).
44. 7. Drywall Corner Clips
Cost Savings
● Typical new house: $16
● Material savings, per floor
= ($3) x (number of inside corners)
● Labour savings = 0
45. 8. Non-Load Bearing Partition Walls
Background
● Non-load bearing partition walls are typically constructed
of 38x89 (2x4) members spaced at 400 mm (16”). This is
structurally excessive.
● With the exception of plumbing walls (normally built with
38x140’s, 2x6’s) and walls which contain heating ducts,
there is no reason for thicker walls.
46. 8. Non-Load Bearing Partition Walls
OVE/ID Alternative
● Use 38x64 (2x3) studs at 600 mm (24”) o/c instead of
38x89 (2x4) studs for non-load bearing partition walls.
● May be perceived as flimsy construction by some
consumers.
● May require reduced jamb width for doors in partition
walls.
47. 8. Non-Load Bearing Partition Walls
Advantages (to the builder)
● Reduced wood usage.
Advantages (to the homeowner)
● Slight increase in useable floor area.
● Energy saving: none.
48. 8. Non-Load Bearing Partition Walls
Cost Savings
● Typical new house: $125.
● Material savings, per floor (imperial units)
= (2) x (wall perimeter, ft) x (2x4 stud cost per foot)
Material savings, per floor (metric units)
=(2) x (wall perimeter, m) x (38x89 stud cost per metre)
● Labour savings = 0
49. 9. Coordinated Framing For Window
And Doors
Background
● The locations of windows and doors are usually dictated by aesthetic
concerns with little thought about the impact on framing.
● By making slight lateral adjustments to the locations of windows & doors
(on at least one side) to align with the existing stud spacing, the framing
can often be simplified and unnecessary studs and cripples eliminated.
50. 9. Coordinated Framing For Window
And Doors
OVE/ID Alternative
● Modify the positions of windows and doors slightly so that
existing studs form one side of the rough-openings.
● This practice complies with the structural requirements
in the NBC.
4 members
5 members
Why not
9 members?
51. 9. Coordinated Framing For Window
And Doors
Advantages (to the builder)
● Reduced wood usage.
Advantages (to the homeowner)
● Reduced thermal bridging.
● Energy saving: average of 130 kWhe/yr
(worth $7 to $14 per year).
.
52. 9. Coordinated Framing For Window
And Doors
Cost Savings
● Typical new house: $95.
● Material savings
= [(2 x number of windows) + (number of doors)] x (wall stud cost)
● Labour savings = 0.3 x (material savings)
53. 10. Elimination Of Lintels In
Non-Load Bearing Walls
OVE/ID Alternative
● Eliminate all lintels in non-load bearing walls.
54. 10. Elimination Of Lintels In
Non-Load Bearing Walls
Advantages (to the builder)
● Reduced wood usage.
Advantages (to the homeowner)
● Reduced thermal bridging.
● Energy saving: average of 125 kWhe/yr
(worth $6 to $12 per year).
.
55. 10. Elimination Of Lintels In
Non-Load Bearing Walls
Cost Savings
● Typical new house: $35.
● Material savings (imperial units)
= 1.4 x ( number of doors & windows) x (lintel cost per lineal foot)
Material savings (metric units),
= 0.4 x ( number of doors & windows) x (lintel cost per lineal metre)
● Labour savings = 0.7 x (material savings)
56. 11. Simplified Plumbing System
Stack Venting
Background
● Plumbing walls are normally constructed with 38x140 (2x6)
framing to provide space for plumbing vents and water lines.
● If the house uses a floor plan in which the bathrooms,
kitchen and laundry rooms are dispersed, then more than
one plumbing wall may be required.
57. 11. Simplified Plumbing System
Stack Venting
OVE/ID Alternative
● Cluster the wet rooms (bathrooms, kitchen and laundry
room) around one plumbing wall.
Non-clustered
Clustered
58. 11. Simplified Plumbing System
Stack Venting
Advantages (to the builder)
● Reduced wood usage.
Advantages (to the homeowner)
● Reduced air leakage (plumbing walls
tend to be extremely leaky).
● Slight increase in useable floor space
● Energy saving: none.
.
59. 11. Simplified Plumbing System
Stack Venting
Cost Savings
● Typical new house: $50.
● Total savings (materials and labour),
= 50 x ( number of plumbing walls eliminated)
Air leakage occurring through a
plumbing wall into the attic
60. 12. Core Distribution For Forced Air
Heating Systems
Background
● Heating grilles and registers are normally located under
windows to help keep them free of condensation - which
requires additional ductwork to reach the perimeter.
● However, this practice began when windows were
single-or-double glazed. Today’s windows are much more
resistant to condensation.
● Also, today’s building envelopes are much better insulated
and more airtight than their predecessors.
61. 12. Core Distribution For Forced Air
Heating Systems
OVE/ID Alternative
● Cluster the heating system grilles and registers around the central
core of the house, close to the furnace.
● Use high sidewall supplies, running through partition walls, if necessary.
High Sidewall Supply
Conventional Perimeter
Distribution System
62. 12. Core Distribution For Forced Air
Heating Systems
Advantages (to the builder)
● Reduced labour and material costs.
● Simplifies the house design since some of the usual
conflict between the heating/plumbing systems and
the structural design of the house is eliminated.
Advantages (to the homeowner)
● Fewer problems with furniture placement, especially
if high sidewall supplies are used.
● Energy saving: (probably) none.
.
63. 12. Core Distribution For Forced Air
Heating Systems
Cost Savings
● Typical new house: $285.
● Total savings (materials and labour), (imperial units),
= 25 x (floor area* / 125)
Total savings (materials and labour), (metric units),
= 25 x (floor area* / 12)
* = exclusive of basement area
64. 13. Optimized Window Selection
Background
● Windows are usually the single most expensive component of the
the building envelope.
● The optimum window for a house can be defined as one which gives
the best compromise between cost and energy performance while
still achieving the desired durability.
● Numerous technologies (low-E films, gas fills, insulated spacers, etc.)
are commonly available which improve energy performance but
increase costs – sometimes significantly.
● Their performance depends on the house and its location.
● But, these treatments have wildly different costs. Which is the best
window for a given house in a given location?
65. 13. Optimized Window Selection
OVE/ID Alternative
● Analyze the performance of various window options
using for the proposed house using HOT2000 (or
equivalent) and select the most cost- effective solution.
66. 13. Optimized Window Selection
Advantages (to the builder)
● Reduced costs.
Advantages (to the homeowner)
● Improved comfort.
● Energy saving: potentially significant – up to 1000 kWh e/yr
.
67. 13. Optimized Window Selection
Cost Savings
● Typical new house: potentially up to $1500, although this will vary
greatly. Savings are dependent upon the house and its location.
Window Costs*:
$13,300
$ 4,100
$ 4,200
$ 5,200
• All costs quoted by the
same manufacturer
69. Example Of Measure #1
Exterior Wall Framing at 600 mm (24”) o/c
Assume a two-storey house with wall perimeters of 40.2 m and 32.3 m and a wall
area of 167 m2. If the studs cost $3.28 each and insulation costs $7.10/m2,
estimate the savings.
Material savings, per floor = (0.82) x (wall perimeter, m) x (stud cost)
- [(0.031) x (wall area) x (cost / m2)]
= (0.82) x (40.2 + 32.3) x (3.28) – [(0.031) x 167 x 7.10] = $158.24
Labour savings = 1.2 x (material savings)
= 1.2 x $158.24 = $189.89
Total savings = $158.24 + $189.89 = $348.13
70. Example Of Measure #2
Floor Framing at 600 mm (24”) o/c
Assume a two-storey house with a floor area of 141 m2. If the floor joists cost
$3.15 per metre, estimate the savings.
Material savings, per floor = (0.82) x (floor area, m2) x (joist cost per metre)
= (0.82) x (141) x (3.15) = $364.20
Labour savings = 0.47 x (material savings)
= 0.47 x $364.20 = $171.17
Total savings = $364.20 + $171.17 = $535.37
71. Example Of Measure #5
Elimination Of Floor System Cross-Bridging
Assume a two-storey house with a floor area of 141 m2. If the cross-bridging
costs $0.44 per metre, estimate the savings.
Material savings = [(floor area, m2) / (1.6)] x (cross-bracing cost per metre)
= [(141 / 1.6)] x (0.44) = $39.90
Labour savings = 1.9 x (material savings)
= 1.9 x $39.90 = $75.81
Total savings = $39.90 + $75.81 = $115.71
72. Example Of Measure #12
Elimination Of Lintels In Non-Load Bearing Walls
Assume a house with 20 windows and 4 doors. If the cost per metre of the
38x184 (2x8) material used for the lintels is $2.03, estimate the savings.
Material savings, per floor = (0.4) x [(no. of windows) + (no. of doors)]
x (lintel cost per lineal metre)
= (0.4) x (20 + 4) x (2.03 x 2) = $38.98
Note: since the lintel is composed of 2-38x184 (2x8) members, the cost per lintel
is equal to (2.03 x 2).
Labour savings = 0.7 x (material savings)
= 0.7 x $38.98 = $27.28
Total savings = $38.98 + $27.28 = $66.26
73. Example Of Measure #14
Core Distribution For Forced Air Heating Systems
Assume a two-storey house with perimeter air distribution system and a floor
area of 141 m2. Estimate the savings of a core air distribution system.
Total savings = 25 x (floor area, m2 / 12)
= 25 x (141 / 12) = $293.75
74. SUMMARY – WHAT HAVE WE LEARNED?
Optimum Value Engineering and Integrated Design are simply applied
common sense (this ain’t rocket science). They have been successfully
used in thousands of buildings over several decades.
Disadvantages
● They require re-thinking of conventional construction practices.
● OVE/ID introduces changes to the construction process (“change” = $).
● Consumers may have a negative reaction – “less material means
cheaper construction?”
Advantages
● OVE/ID saves the builder money.
● OVE/ID saves the homeowner energy and money.
● OVE/ID saves resources.